JP2013203895A - Method for producing polymer compound, resist composition, and resist pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel method for producing a polymer compound having a structural unit which is decomposed by exposure to generate an acid, a resist composition containing the polymer compound, and a resist pattern forming method using the resist composition.SOLUTION: A method for producing a polymer having a structural unit which is decomposed by exposure to generate an acid includes steps of: reacting a first precursor polymer having a first ammonium cation with an amine having an acid dissociation constant (pKa) of conjugate acid larger than the first ammonium cation to form a second precursor polymer having a second ammonium cation that is a conjugate acid of the amine; and salt-exchanging the second precursor polymer with a sulfonium cation or iodonium cation. The second ammonium cation is lower in hydrophobicity than the first ammonium cation, and lower in hydrophobicity than the sulfonium cation or iodonium cation.

Description

  The present invention relates to a method for producing a polymer compound useful as a base component of a resist composition, a resist composition containing the polymer compound, and a resist pattern forming method using the resist composition.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed and developed to form a resist pattern having a predetermined shape on the resist film. The process to perform is performed. A resist material in which the exposed portion of the resist film changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the exposure light source is generally shortened in wavelength (increased energy). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has been started. Further, studies have been made on EUV (extreme ultraviolet), EB (electron beam), X-rays and the like having shorter wavelengths (higher energy) than these excimer lasers.

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions.
Conventionally, as a resist material satisfying such requirements, there is a chemically amplified resist composition containing a base material component whose solubility in a developing solution is changed by the action of an acid and an acid generator component that generates an acid upon exposure. It is used.
For example, when the developer is an alkali developer (alkaline development process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkali developer is increased by the action of an acid, an acid Those containing a generator component are generally used. When a resist film formed using such a resist composition is selectively exposed at the time of forming a resist pattern, an acid is generated from the acid generator component in the exposed portion, and the acid acts on the alkaline developer of the base resin. Solubility increases and the exposed part becomes soluble in an alkaline developer. Therefore, by performing alkali development, a positive pattern in which an unexposed portion remains as a pattern is formed. Here, as the base resin, a resin whose polarity is increased by the action of an acid is used, and the solubility in an alkali developer is increased while the solubility in an organic solvent is decreased.
On the other hand, when a solvent development process using an organic solvent-containing developer (organic developer) is applied instead of an alkali development process, the solubility in the organic developer is relatively reduced in the exposed area. In the solvent development process, the unexposed portion of the resist film is dissolved and removed by the organic developer, and a negative resist pattern is formed in which the exposed portion remains as a pattern. Such a solvent development process for forming a negative resist pattern is sometimes referred to as a negative development process (see, for example, Patent Document 1).

At present, as a base resin of a chemically amplified resist composition used in ArF excimer laser lithography and the like, it has a structural unit derived from (meth) acrylic acid ester in its main chain because of its excellent transparency near 193 nm. Resins (acrylic resins) and the like are generally used (see, for example, Patent Document 2).
Here, “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position. “(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.

In recent years, a base resin having an acid generating group that decomposes upon exposure to generate an acid has been proposed. For example, a polymer obtained by copolymerizing a monomer having an acid-generating group that generates an acid upon exposure and a monomer having an acid-decomposable group whose polarity is changed by the action of an acid has been proposed (for example, a patent) Reference 3).
Such a polymer has both a function as an acid generator and a function as a base component, and can constitute a chemically amplified resist composition with one component. In other words, when the polymer is exposed to light, an acid is generated from the acid-generating group in the structure, the acid-decomposable group is decomposed by the action of the acid, and a polar group such as a carboxy group is generated to increase the polarity. To do. Therefore, when selective exposure is performed on a resist film formed using the polymer, the polarity of the exposed portion increases. Therefore, the exposed portion is dissolved and removed by developing with an alkaline developer. A positive resist pattern is formed, and development is performed using an organic developer to dissolve and remove unexposed portions to form a negative resist pattern.

JP 2009-25707 A JP 2003-241385 A International Publication No. 2006/121096

  According to the polymer having an acid-generating group and an acid-decomposable group as described in Patent Document 3, the resolution is higher than when the acid generator and the base component are blended separately. It is supposed to improve. The reason why the resolution is improved is that the base resin, which is a base material component, has an acid-generating group, and the acid-generating group is easily distributed uniformly in the resist film. It is conceivable that the acid to be easily diffused uniformly in the resist film. Such a polymer having an acid-generating group and an acid-decomposable group is generally produced by a normal radical polymerization method or the like using a monomer that induces a repeating unit constituting the polymer.

However, when a polymer having an acid-generating group and an acid-decomposable group as described above is produced by an ordinary radical polymerization method or the like, a monomer having an acid-generating group and a monomer having an acid-decomposable group are used together. When polymerized, there is a problem that a desired polymer cannot be produced depending on the type of monomer having an acid generating group.
The present invention has been made in view of the above circumstances, and is a novel method for producing a polymer compound having a structural unit that decomposes upon exposure to generate an acid, and a resist composition containing the polymer compound, It is another object of the present invention to provide a resist pattern forming method using the resist composition.

  When the inventors of the present invention produce a polymer compound having a structural unit that decomposes by exposure to generate an acid, when the monomer having an acid generating group that generates an acid by exposure and another monomer are directly radically polymerized, It was confirmed that there was a problem that the polymerization did not proceed depending on the structure of the cation part of the monomer having an acid generating group. In contrast, the present inventors have studied and synthesized a precursor polymer having a low hydrophobic ammonium cation by utilizing the difference in acid dissociation constant (pKa) of the conjugate acid, and utilized the difference in hydrophobicity. Then, it was found that a desired polymer compound can be produced by performing salt exchange for introducing a predetermined cation, and the present invention was completed. That is, the present invention employs the following configuration.

  In the first aspect of the present invention, a first precursor polymer having a first ammonium cation is reacted with an amine whose acid dissociation constant (pKa) of the conjugate acid is larger than that of the first ammonium cation. A step of obtaining a second precursor polymer having a second ammonium cation which is a conjugate acid of the amine, and a step of salt-exchange of the second precursor polymer with a sulfonium cation or an iodonium cation, The second ammonium cation is lower in hydrophobicity than the first ammonium cation and lower in hydrophobicity than the sulfonium cation or iodonium cation, and generates an acid upon decomposition upon exposure. It is a manufacturing method of the high molecular compound which has a unit.

  According to a second aspect of the present invention, there is provided a resist composition comprising the polymer compound produced by the polymer compound production method of the first aspect.

  According to a third aspect of the present invention, a resist film is formed on a support using the resist composition of the second aspect, the resist film is exposed, and the resist film is developed to form a resist. It is a resist pattern formation method characterized by including the process of forming a pattern.

  According to a fourth aspect of the present invention, there is provided a first precursor polymer having a first ammonium cation, an acid dissociation constant (pKa) of the conjugate acid being larger than that of the first ammonium cation, and a hydrophobic property of the conjugate acid. It is a method for producing a polymer compound, which comprises reacting with an amine having a property lower than that of the first ammonium cation.

In the present specification and claims, “exposure” is a concept including general irradiation of radiation.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
“Halogenated alkyl group” is a group in which some or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. “Halogenated alkylene group” is in which some or all of the hydrogen atoms in the alkylene group are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
A “fluorinated alkyl group” is a group in which some or all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms. A “fluorinated alkylene group” is a group in which some or all of the hydrogen atoms in the alkylene group are substituted with fluorine atoms. Group.
In the present specification, “polymer compound” or “resin” refers to a polymer having a molecular weight of 1000 or more. In the case of a polymer compound, the “molecular weight” is a polystyrene-reduced mass average molecular weight measured by GPC (gel permeation chromatography).
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).

  ADVANTAGE OF THE INVENTION According to this invention, the novel manufacturing method of the high molecular compound which has a structural unit which decomposes | disassembles by exposure and generates an acid, the resist composition containing the said high molecular compound, and the resist pattern using the said resist composition A forming method can be provided.

≪Method for producing polymer compound≫
The method for producing a polymer compound of the present invention comprises reacting a first precursor polymer having a first ammonium cation with an amine having a conjugate acid acid dissociation constant (pKa) larger than that of the first ammonium cation. Then, a step of obtaining a second precursor polymer having a second ammonium cation which is a conjugate acid of the amine (hereinafter, this step is referred to as “amine reaction step”), the second precursor polymer, and sulfonium And a step of salt exchange with a cation or an iodonium cation (hereinafter, this step is referred to as “salt exchange step”).
The polymer compound produced by this production method has a structural unit that decomposes upon exposure to generate an acid. The structural unit that decomposes upon exposure to generate an acid has a cation portion and an anion portion, and the cation portion has a sulfonium cation or an iodonium cation. Such a polymer compound is suitable as a base resin used as a base component of a resist composition.
In the production method according to the present invention, in consideration of the hydrophobicity of the sulfonium cation or iodonium cation contained in the polymer compound of the final target product, the first ammonium cation having a first ammonium cation satisfying a predetermined relationship between pKa and hydrophobicity. These precursor polymers, amines, and salt exchange compounds are selected and used in combination.

[Amine reaction step]
In the amine reaction step, the first precursor polymer having a first ammonium cation is reacted with an amine having a pKa of the conjugate acid larger than that of the first ammonium cation, and the second is a conjugate acid of the amine. To obtain a second precursor polymer having an ammonium cation.
In the present invention, the “ammonium cation” means NH ₄ ⁺ , or a cation (primary to quaternary ammonium cation) in which H is substituted with a hydrocarbon group which may have a hetero atom, or the like A cyclic cation that forms a ring with N.

(Amine)
The amine used for the reaction with the first precursor polymer in the amine reaction step has a pKa of the conjugate acid (which becomes the second ammonium cation) larger than that of the first ammonium cation, and the conjugate acid (the second acid cation). The second ammonium cation) is less hydrophobic than the first ammonium cation.
In addition, the conjugate acid (second ammonium cation) is less hydrophobic than the sulfonium cation or iodonium cation used in the salt exchange step after the amine reaction step, and can be exchanged with these sulfonium cation or iodonium cation. Is.
By reacting such amine with the first precursor polymer, a cation to be finally contained (sulfonium cation or iodonium cation used for salt exchange with the second precursor polymer in the salt exchange step, hereinafter referred to as “final sulfonium”. Alternatively, a cation having a lower hydrophobicity than the iodonium cation ”) is introduced.

In the present invention, the “hydrophobicity of the cation” can be compared by the retention time (retention time) when two or more target cations are analyzed under the same conditions by a high performance liquid chromatography (HPLC) method. In the present invention, in the measurement by HPLC method, a cation having a relatively long retention time is referred to as a “highly hydrophobic cation”, and a cation having a relatively short retention time is referred to as a “low hydrophobic cation”.
The apparatus and conditions used for the HPLC method are not particularly limited as long as they are general apparatuses and conditions used for analyzing a compound and can analyze the target cation. Specifically, it can be measured under the following conditions.
Eluent (developing solvent): acetonitrile / buffer solution (50/50 volume ratio).
Buffer solution: 0.1 mass% trifluoroacetic acid aqueous solution.
Apparatus: Dionex U3000 (manufactured by Dionex).
Column: Superiorex ODS (manufactured by Shiseido); column length 25 cm.
Detector: Corona CAD (manufactured by ESA Biosciences).
Flow rate: 1 mL / min.
Column temperature: 30 ° C.
Sample concentration: acetonitrile solution having a solid content of 0.1% by mass.
Injection volume: 2 μL.
The sample concentration indicates a solid content concentration of a compound in which the anion is Br ⁻ and the cation has various target structures.

Regarding the amine conjugate acid (second ammonium cation), the retention time (retention time) measured under the specific conditions of the HPLC method is preferably 1 to 3.5 minutes, and 1.5 to 3 Minutes are more preferred, and 1.5 to 2.5 minutes are even more preferred.
If the retention time is not less than the preferred lower limit, the solubility in an organic solvent becomes better. On the other hand, if the retention time is not more than the preferred upper limit, a salt with a sulfonium salt or iodonium salt in the salt exchange step. Easy to perform exchange reaction.

The amine conjugate acid (second ammonium cation) preferably has a retention time relatively shorter than 0.2 minutes (faster) and shorter than 0.3 minutes (faster) than the final sulfonium or iodonium cation. Is more preferable.
Since the retention time is relatively short for 0.2 minutes or more, a salt exchange reaction with a sulfonium salt or an iodonium salt in the salt exchange step is facilitated.

  In the present invention, “pKa” is an acid dissociation constant and is generally used as an index indicating the acid strength of a target substance. The pKa value of a cation (ammonium cation, amine conjugated acid) can be determined by measurement by a conventional method. It can also be estimated by calculation using known software such as “ACD / Labs” (trade name, manufactured by Advanced Chemistry Development).

The amine conjugate acid (second ammonium cation) can be obtained, for example, from a simulation using the above software (ACD / Labs, Software V11.02 as an example).
The pKa of the amine conjugate acid (second ammonium cation) is preferably 2 or more, and more preferably 3 or more, larger than the pKa of the first ammonium cation.
Since pKa is relatively larger by 2 or more, the reaction between the first precursor polymer and the amine is sufficiently facilitated.

The pKa of a specific amine conjugate acid (second ammonium cation) is preferably 7.5 or more, more preferably 8 to 20, and still more preferably 8.5 to 18.
When the pKa is at least the preferred lower limit, it becomes a relatively strong base. On the other hand, when the pKa is at most the preferred upper limit, the stability of the polymer during or after the polymerization reaction is further improved.

  Examples of the amine to be the second ammonium cation include cyclic amines such as cyclic amidines and cyclic tertiary alkylamines, in addition to those represented by the following general formula (ca2-1).

［式中、Ｒ^１、Ｒ^２及びＲ^３はそれぞれ独立に水素原子または置換基を有していてもよい炭素数１〜１５のアルキル基、アラルキル基もしくは含窒素複素環式基である。］

[Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, an aralkyl group or a nitrogen-containing heterocyclic group which may have a substituent. ]

In the formula (ca2-1), examples of the alkyl group in R ¹ , R ² and R ³ include a linear, branched or cyclic alkyl group, and a linear or branched alkyl group is preferable. . The alkyl group in R ¹ , R ² and R ³ has 1 to 15 carbon atoms, preferably 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, n-butyl. Group, isobutyl group, tert-butyl group, pentyl group, isopentyl group and neopentyl group are preferred, and ethyl group and isopropyl group are more preferred.
As the aralkyl group in R ¹ , R ² and R ³ , a benzyl group or a naphthylmethyl group is preferable.
The nitrogen-containing heterocyclic group in R ¹ , R ² and R ³ may be an aromatic group or an aliphatic group. The nitrogen-containing heterocyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring, and examples thereof include a pyridine cyclic group and a triazine cyclic group.
Examples of the substituent that R ¹ , R ^2, and R ³ may have include an alkyl group, an alkoxy group, a hydroxyl group, an oxo group (═O), and an amino group. The alkyl group and alkoxy group each preferably have 1 to 5 carbon atoms.

  Specific examples of the amine represented by the general formula (ca2-1) are shown below.

In addition, each conjugate acid in the specific example of the amine, the retention time (retention time) of the conjugate acid, and pKa are shown below.
In addition, the retention time (retention time) shown with a chemical structure is the value measured on the specific conditions of the said HPLC method. In addition, pKa indicates a simulation result using ACD / Labs, Software V11.02 (trade name, manufactured by Advanced Chemistry Development).
About the retention time of the conjugate acid of the amine which is not shown below, since all have high hydrophilicity, it is assumed that it is within 1-3 minutes (3.5 minutes at the longest). In addition, the pKa is 7.5 or more because all of them are strong bases (pKa is 7.7 for a conjugate acid of triethanolamine).

(First precursor polymer)
The first precursor polymer has a first ammonium cation and an anionic group that generates an acid upon exposure.

-About the first ammonium cation The first ammonium cation has a pKa smaller than that of the amine conjugate acid (second ammonium cation) used in the amine reaction step and is more hydrophobic than the amine conjugate acid. It is.

For the first ammonium cation, the retention time (retention time) measured under the specific conditions of the HPLC method described above is the precursor polymer (precursor of the first precursor polymer: third precursor polymer). It is necessary to consider only when the first precursor polymer is obtained through the above process.
The retention time of the first ammonium cation is preferably longer than the retention time of a cation (such as a sulfonium cation) in the third precursor polymer. Specifically, 3 minutes or more is preferable, and 3.5 minutes or more is more preferable. The upper limit is not particularly limited, but is preferably 60 minutes or less.
If the retention time is equal to or more than the preferred lower limit, the salt exchange reaction between the third precursor polymer and the first ammonium cation tends to proceed. The holding time is preferably as long as possible.
In addition, with respect to the retention time difference between the first ammonium cation and the cation (sulfonium cation, etc.) in the third precursor polymer, the retention time of the first ammonium cation is preferably 10 seconds or more, more preferably It is preferably 20 seconds or longer.

For the first ammonium cation, for example, the pKa by simulation using the above-mentioned software (for example, ACD / Labs, Software V11.02) is preferably lower than the second ammonium cation, specifically, , Less than pKa8 is preferable, more than 0 and 7.5 or less is more preferable, and 1 to 7 is more preferable.
When the pKa is at most the preferred upper limit, the reaction with the amine proceeds easily. On the other hand, when the pKa is at least the preferred lower limit, the stability of the polymer during the polymerization reaction or after the polymerization is further improved.

  The first ammonium cation preferably has an electron-withdrawing group in order to reduce the pKa of the conjugate acid and facilitate the reaction with the amine. The suitable example is shown below.

［式中、Ｒ^８〜Ｒ^１０はそれぞれ独立に水素原子又は置換基を有していてもよい炭素数１〜１５のアルキル基、フッ素化アルキル基もしくはアリール基であり、少なくとも１つはフッ素化アルキル基またはアリール基である。Ｒ^１１は、当該Ｒ^１１が結合した窒素原子と共に芳香環を形成する基であり、Ｒ^１２は炭素数１〜１５のアルキル基またはハロゲン原子であり、ｙは０〜５の整数である。］

[Wherein R ^{8 to} R ¹⁰ are each independently a hydrogen atom or an optionally substituted alkyl group having 1 to 15 carbon atoms, a fluorinated alkyl group or an aryl group, and at least one of them is fluorinated. An alkyl group or an aryl group; R ¹¹ is a group that forms an aromatic ring together with the nitrogen atom to which R ¹¹ is bonded, R ¹² is an alkyl group having 1 to 15 carbon atoms or a halogen atom, and y is an integer of 0 to 5. ]

In the formula (ca1-1), examples of the alkyl group in R ^{8 to} R ¹⁰ include a linear, branched, or cyclic alkyl group, and a linear or branched alkyl group is preferable, and a linear chain is preferable. The alkyl group is more preferable. The number of carbon atoms in the alkyl group in R ⁸ to R ¹⁰ is 1 to 15. When the first precursor polymer is obtained via the third precursor polymer, the larger the number of carbon atoms, the higher the hydrophobicity, which is preferable, but industrially, preferably the number of carbon atoms is 1 to 5. Preferred examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group and neopentyl group. When two of R ^{8 to} R ¹⁰ are alkyl groups, they may be bonded to each other to form a ring.
The alkyl group of the fluorinated alkyl group in R ^{8 to} R ¹⁰ is the same as described above, and the fluorination rate is preferably 50% or more, and more preferably 75% or more.
As an aryl group in R < ⁸ > -R < ¹⁰ >, a phenyl group and a naphthyl group are preferable.
When at least one of R ^{8 to} R ¹⁰ is a fluorinated alkyl group or an aryl group, the tendency toward weak basicity is increased, and the reaction for forming the second precursor polymer is likely to proceed.
In addition, when the first precursor polymer is obtained via the third precursor polymer, it is preferable that at least one of R ^{8 to} R ¹⁰ is an aryl group to improve hydrophobicity (increase the holding time). In view of facilitating the salt exchange reaction between the cation and the first ammonium cation in the third precursor polymer.
When only R ¹⁰ is a fluorinated alkyl group or an aryl group among R ^{8 to} R ¹⁰ , the remaining R ⁸ and R ⁹ are preferably a hydrogen atom or an alkyl group, and are preferably a hydrogen atom or an n-butyl group. Is more preferable. In addition, it is further preferred that R ⁸ and R ⁹ are the same.

In the formula (ca1-2), R ¹¹ is a group that forms an aromatic ring together with the nitrogen atom to which R ¹¹ is bonded. The aromatic ring is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring, and even more preferably a 6-membered ring.
R ¹² is an alkyl group having 1 to 15 carbon atoms, and preferably the same as described above. When the first precursor polymer is obtained via the third precursor polymer, the alkyl group of R ¹² is preferably as having a larger carbon number in terms of increasing hydrophobicity, but industrially tert-butyl is preferred. Groups are preferred.
The halogen atom for R ¹² is preferably a fluorine atom.
y is an integer of 0 to 5, an integer of 0 to 2 is preferable, and 2 is particularly preferable.

Specific examples of the first ammonium cation represented by the general formula (ca1-1) and the general formula (ca1-2) are shown below.
In addition, the retention time (retention time) shown with a chemical structure is the value measured on the specific conditions of the said HPLC method. The holding time needs to be considered only when the first precursor polymer is obtained via the third precursor polymer. In order to maintain the retention time for at least 3 minutes, at least one of R ^{8 to} R ¹⁰ in the formula (ca1-1) is an aryl group, and the remaining group is an alkyl group; It is preferable that R ¹² in -2) is an alkyl group, and y is 1 or more.
pKa indicates a simulation result using ACD / Labs, Software V11.02 (trade name, manufactured by Advanced Chemistry Development).

-Anion group In the first precursor polymer, the anion group that generates an acid upon exposure is not particularly limited, but a sulfonate anion, a carboxylic acid anion, a sulfonylimide anion, and a bis (alkylsulfonyl) imide. It is preferably at least one group selected from the group consisting of an anion and a tris (alkylsulfonyl) methide anion.
Among these, the anionic group is preferably any one of groups represented by the following formulas (an1) to (an4).

［式中、Ｗ^０は置換基を有していてもよい炭素数１〜３０の炭化水素基である。Ｚ^３は−Ｃ（＝Ｏ）−Ｏ−、−ＳＯ_２−又は置換基を有していてもよい炭化水素基であり、Ｚ^４及びＺ^５はそれぞれ独立に−Ｃ（＝Ｏ）−又は−ＳＯ_２−である。Ｒ^６２及びＲ^６３はそれぞれ独立にフッ素原子を有していてもよい炭化水素基である。Ｚ^１は−Ｃ（＝Ｏ）−、−ＳＯ_２−、−Ｃ（＝Ｏ）−Ｏ−又は単結合であり、Ｚ^２は−Ｃ（＝Ｏ）−又は−ＳＯ_２−である。Ｒ^６１はフッ素原子を有していてもよい炭化水素基である。Ｒ^６４はフッ素原子を有していてもよい炭化水素基である。］

[Wherein, W ⁰ represents a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent. Z ³ is —C (═O) —O—, —SO ₂ — or an optionally substituted hydrocarbon group, and Z ⁴ and Z ⁵ are each independently —C (═O) — or -SO ₂ - is. R ⁶² and R ⁶³ are each independently a hydrocarbon group optionally having a fluorine atom. Z ¹ is —C (═O) —, —SO ₂ —, —C (═O) —O— or a single bond, and Z ² is —C (═O) — or —SO ₂ —. R ⁶¹ is a hydrocarbon group which may have a fluorine atom. R ⁶⁴ is a hydrocarbon group which may have a fluorine atom. ]

In formula (an1), W ⁰ is a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent.
The hydrocarbon group having 1 to 30 carbon atoms which may have a substituent of W ⁰ may be an aliphatic hydrocarbon group or an aromatic group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group for W ⁰ include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in the structure.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 5 carbon atoms.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxo group (═O).

As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
The cyclic aliphatic hydrocarbon group (aliphatic cyclic group) preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, Examples include norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (═O).
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.

The aromatic group in W ⁰ is a divalent hydrocarbon group having at least one aromatic ring and may have a substituent.
The aromatic ring in W ⁰ is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are more preferable, and 6-12 are especially preferable. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; etc. Is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic group in W ⁰ is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); an aromatic group containing two or more aromatic rings A group obtained by removing two hydrogen atoms from a compound (for example, biphenyl, fluorene, etc.); a hydrogen atom of a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle A group substituted with an alkylene group (for example, an aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc. A group in which one hydrogen atom is further removed); The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.
The aromatic group may or may not have a substituent. For example, a hydrogen atom bonded to an aromatic ring of the aromatic group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (═O).
The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent are the same as the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the cyclic aliphatic hydrocarbon group. It is.
Especially, group represented by a following formula (an1-1) is preferable.

［式中、Ｒ^ｆ１及びＲ^ｆ２はそれぞれ独立に水素原子、アルキル基、フッ素原子、又はフッ素化アルキル基であり、Ｒ^ｆ１、Ｒ^ｆ２のうち少なくとも１つはフッ素原子又はフッ素化アルキル基であり、ｐ０は１〜８の整数である。］

[Wherein, R ^f1 and R ^f2 each independently represent a hydrogen atom, an alkyl group, a fluorine atom, or a fluorinated alkyl group, and at least one of R ^f1 and R ^f2 is a fluorine atom or a fluorinated alkyl group. , P0 is an integer of 1-8. ]

R ^f1 and R ^f2 are each independently a hydrogen atom, an alkyl group, a fluorine atom, or a fluorinated alkyl group, and at least one of R ^f1 and R ^f2 is a fluorine atom or a fluorinated alkyl group.
As the alkyl group for R ^f1 and R ^f2 , an alkyl group having 1 to 5 carbon atoms is preferable, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group. Group, pentyl group, isopentyl group, neopentyl group and the like.
Examples of the fluorinated alkyl group of ^{R f1,} R ^f2, group in which part or all of the hydrogen atoms of the alkyl group of the ^{R f1, R f2} is substituted with a fluorine atom is preferred.
R ^f1 and R ^f2 are preferably a fluorine atom or a fluorinated alkyl group.
In formula (an1-1), p0 is an integer of 1 to 8, preferably an integer of 1 to 4, and more preferably 1 or 2.

Further, as the substituent hydrocarbon group which may have a W ^0, preferred examples other than the above formula (an1-1) is which may have a substituent aliphatic cyclic group or an aromatic It is preferably a group, and is a group in which two or more hydrogen atoms are removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, camphor, benzene or the like (which may have a substituent). It is more preferable.

In formula (an2), Z ³ represents —C (═O) —O—, —SO ₂ — or a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group which may have a substituent for Z ³ include the same hydrocarbon groups as those having 1 to 30 carbon atoms which may have a substituent for W ⁰ . Among these, Z ³ is preferably —SO ₂ —.
In formula (an2), Z ⁴ and Z ⁵ are each independently —C (═O) — or —SO ₂ —, preferably at least one is —SO ₂ —, and both are —SO _2. -Is more preferable.
R ⁶² and R ⁶³ are each independently a hydrocarbon group which may have a fluorine atom, and examples thereof include those similar to the hydrocarbon group which may have a fluorine atom in R ⁶¹ described later. .

In formula (an3), Z ¹ represents —C (═O) —, —SO ₂ —, —C (═O) —O—, or a single bond. When Z ¹ is a single bond, N ^{− in} the formula is preferably not directly bonded to —C (═O) — on the side opposite to the side bonded to Z ² (that is, the left end in the formula).
In formula (an3), Z ² represents —C (═O) — or —SO ₂ —, and preferably —SO ₂ —.

R ⁶¹ is a hydrocarbon group which may have a fluorine atom. Examples of the hydrocarbon group for R ⁶¹ include an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, and an aralkyl group.
The alkyl group for R ⁶¹ is preferably one having 1 to 8 carbon atoms, more preferably one having 1 to 6 carbon atoms, still more preferably one having 1 to 4 carbon atoms, and even if linear, it is branched. It may be a chain. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group and the like are preferable.
The monovalent alicyclic hydrocarbon group in R ⁶¹ is preferably those having 3 to 20 carbon atoms, more preferably those having 3 to 12 carbon atoms, and may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclobutane, cyclopentane, and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms. Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
The aryl group in R ⁶¹ is preferably those having 6 to 18 carbon atoms, more preferably those having 6 to 10 carbon atoms, and particularly preferably a phenyl group.
Aralkyl group in R ⁶¹ include those in which the "aryl group for R ^61" alkylene group and the above C1-8 bonded are preferred examples. More preferred is an aralkyl group in which an alkylene group having 1 to 6 carbon atoms and the above “aryl group in R ⁶¹ ” are bonded, and an aralkyl group in which an alkylene group having 1 to 4 carbon atoms and the above “aryl group in R ⁶¹ ” are bonded. Is particularly preferred.
In the hydrocarbon group for R ⁶¹ , part or all of the hydrogen atoms of the hydrocarbon group are preferably substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms. More preferably. Especially, it is especially preferable that it is the perfluoroalkyl group by which all the hydrogen atoms of the alkyl group mentioned above were substituted by the fluorine atom.

In the formula (an4), R ⁶⁴ represents a hydrocarbon group that may have a fluorine atom. As the hydrocarbon group for R ⁶⁴ , an alkylene group, a divalent alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from an aryl group, a group in which one or more hydrogen atoms have been removed from an aralkyl group, etc. Is mentioned.
Specific examples of the hydrocarbon group for R ⁶⁴ include those exemplified in the description of the hydrocarbon group for R ⁶¹ (an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, an aralkyl group, and the like). And a group in which one or more hydrogen atoms are removed.
In the hydrocarbon group for R ⁶⁴ , part or all of the hydrogen atoms of the hydrocarbon group are preferably substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms. More preferably.

Among the above, for example, when the anion group is a group having a fluorine atom among the groups represented by the formula (an1) (particularly a group represented by the formula (an1-1)), or represented by the formula (an2) Or a group represented by the formula (an3) in which Z ¹ and Z ² are —SO ₂ —, the fluorinated alkylsulfonate anion, carbanion, sulfonylimide anion is exposed from the anion group by exposure. A relatively strong acid such as can be generated.
On the other hand, when the anion group does not have a fluorine atom among the groups represented by the formula (an1), the group represented by the formula (an4), and Z ¹ and Z ² are —C (═O) —. When it has a group represented by a certain formula (an3), a relatively weak acid such as an alkyl sulfonate anion, an aryl sulfonate anion, a carboxylate anion, and an imide anion can be generated from the anion group by exposure.

Since an acid having a desired acid strength can be generated depending on the type of anionic group as described above, an anionic group is appropriately selected according to the required characteristics of the resist composition using the polymer compound produced according to the present invention. You can choose. For example, when the anion group plays a role similar to that of an acid generator usually used in a resist composition, it is preferable to select an anion group that generates a strong acid.
In addition, for example, when the anion group has the same function as a quencher (a quencher that salt exchanges with a strong acid generated from an acid generator and traps a strong acid) used in a resist composition, a weak acid is generated. It is preferred to select an anionic group.
Here, the strong acid and the weak acid are the relationship with the activation energy of an acid-decomposable group that is decomposed by the action of an acid as contained in the structural unit (a1) described later, and the acid generator acid used together. It is determined in relation to strength. Therefore, the above-mentioned “relatively weak acid” cannot always be used as a quencher.

The first precursor polymer preferably has a structural unit containing the first ammonium cation and the anionic group that generates an acid upon exposure.
This structural unit is derived from a monomer having the first ammonium cation and the anion group that generates an acid upon exposure (hereinafter, this monomer is referred to as “monomer (G)”), or “ It can introduce | transduce into a high molecular compound by the method by salt exchange etc. like the process of obtaining a 1st precursor polymer.
Here, the “structural unit derived from a monomer” means a monomer unit formed by cleavage of an ethylenic double bond in a monomer to form a single bond.
The first precursor polymer may have other structural units as necessary in addition to “the structural unit containing the first ammonium cation and the anionic group that generates an acid upon exposure”. .
Other structural units are not particularly limited as long as they can constitute the first precursor polymer together with “the structural unit containing the first ammonium cation and the anionic group that generates an acid upon exposure”. Among these, a structural unit (a structural unit (a1) described later) containing an acid-decomposable group whose polarity increases by the action of an acid is particularly preferable.
Other structural units include structural units (a2), (a3), and (a4) described later.

(Monomer (G))
Examples of the monomer (G) include those in which the anionic group is directly bonded to a polymerizable group via a linking group or not via a linking group.
Examples of the polymerizable group include vinyl, allyl, acryloyl, methacryloyl, fluorovinyl, difluorovinyl, trifluorovinyl, difluorotrifluoromethylvinyl, trifluoroallyl, perfluoroallyl, Fluoromethylacryloyl group, nonylfluorobutylacryloyl group, vinyl ether group, fluorine-containing vinyl ether group, allyl ether group, fluorine-containing allyl ether group, styryl group, fluorine-containing styryl group, norbornyl group, fluorine-containing norbornyl group, silyl group, etc. It is done.

  Preferred examples of the monomer (G) include compounds represented by the following general formula (I).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｑ^２は単結合又は２価の連結基であり、Ａ⁻はアニオン基であり、Ｍ^＋は第一のアンモニウムカチオンである。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, Q ² represents a single bond or a divalent linking group, and A ⁻ represents an anion group. And M ⁺ is the first ammonium cation. ]

R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
Examples of the halogenated alkyl group having 1 to 5 carbon atoms in R include a group in which part or all of the hydrogen atoms of the aforementioned “alkyl group having 1 to 5 carbon atoms in R” are substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Especially, it is preferable that R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 fluorinated alkyl group, and it is a hydrogen atom or a methyl group from industrial availability. It is particularly preferred.

In the formula, the divalent linking group of Q ² is not particularly limited, but a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like are preferable. It is done.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with a substituent (a group or atom other than a hydrogen atom).
The hydrocarbon group for Q ² may be an aliphatic hydrocarbon group or an aromatic group. Examples of the aliphatic hydrocarbon group and aromatic group in Q ² include the same aliphatic hydrocarbon groups and aromatic groups as those in W ⁰ .

The hetero atom in the “divalent linking group containing a hetero atom” of Q ² is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
As the divalent linking group containing a hetero atom, —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (= O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, —S (═O) _{2 -O -, - NH-C} (= O) -, = N-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -C (= O) -O -, - Y 21 -O- C (═O) —, — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² —, —Y ²¹ —O—C (═O) —Y ²² —, —Y ²¹ —O—Y _{^{22 -O-C (= O)}} -, - Y 21 -O-S (= O) 2 -, - Y 21 -S (= O) 2 -Y 22 -O-S (= O) 2 -, - ^{Y 21 -O-C (= O} ) -Y 22 -O-S (= O) 2 -, - Y 21 -O-Y ^{2 -O-C (= O)} -Y 23 -, - Y 21 -O-S (= O) 2 -Y 22 -, - Y 21 -S-Y 22 -O-S (= O) 2 -Y ²³ -, or ^{-Y 21 -O-C (= O} ) -Y 22 -O-S (= O) 2 -Y 23 - group [wherein represented ^by, Y ^{21, Y 22} and ^{Y 23} are each A divalent hydrocarbon group which may have a substituent independently, O is an oxygen atom, C is a carbon atom, S is a sulfur atom, and m ′ is an integer of 0 to 3. It is. ] Etc. are mentioned.
When Q ² is —NH—, H may be substituted with a substituent such as an alkyl group or an acyl group.
Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those similar to the above-mentioned “divalent hydrocarbon group optionally having substituent (s)” (W ⁰ aliphatic hydrocarbon group, aromatic group).
Y ²¹ is preferably an aliphatic hydrocarbon group or an aromatic hydrocarbon group which may have a substituent, more preferably a linear or cyclic alkylene group, and a linear chain having 1 to 5 carbon atoms. An alkylene group is more preferable, and a methylene group or an ethylene group is particularly preferable.
Y ²² is preferably an aliphatic hydrocarbon group or an aromatic hydrocarbon group which may have a substituent, and includes a methylene group, an ethylene group, an alkylmethylene group, a (poly) cycloalkylene group, a phenylene group, or a naphthylene. Groups are more preferred. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
Y ²³ is preferably a linear or branched aliphatic hydrocarbon group which may have a substituent, and a linear or branched alkylene group which may have a substituent. More preferred.
In the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² —, m ′ is an integer of 0 to 3, preferably an integer of 0 to 2, Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — is represented by the formula —Y ²¹ —C (═O) —O—Y ²² —. The group is particularly preferred. Among these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1.
As the divalent linking group containing a hetero atom, a linear group having an oxygen atom as a hetero atom, for example, a group containing an ether bond or an ester bond, is preferable, and the formula —Y ²¹ —C (═O) — O—, —Y ²¹ —O—C (═O) —, —Y ²¹ —O—Y ²² —, — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —. A group represented by O—C (═O) —Y ²² — is more preferable.

Among the above, as the divalent linking group for Q ² , in particular, a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom is included. preferable. Among these, a linear or branched alkylene group or a divalent linking group containing a hetero atom is more preferable.

In the formula, the anion group of A ⁻ is the same as described above, and groups represented by the above formulas (an1) to (an4) are preferable.
In the formula, M ⁺ is a first ammonium cation and is the same as the first ammonium cation described above.

As an anion group containing monomer, from the group which consists of a compound respectively represented by following formula (an11)-(an14), (an21)-(an25), (an31)-(an32), (an41)-(an44). At least one monomer selected is preferred.
Among these, the compounds represented by the following formulas (an11-1) to (an13-1) are preferable among the compounds represented by the following formulas (an11) to (an14).
In the following formulae, M ⁺ is a first ammonium cation.

［式中、Ｒ、Ｗ^０は前記と同様である。Ｑ^２１は単結合又は２価の連結基である。Ｑ^２２は２価の連結基である。Ｑ^２３は−Ｏ−、−ＣＨ_２−Ｏ−、又は−Ｃ（＝Ｏ）−Ｏ−を含有する基である。Ｒ^ｑ１はフッ素原子又はフッ素化アルキル基である。Ｒ^ａｒは置換基を有していてもよい２価の芳香族基である。Ｒ^ｎは水素原子又は炭素数１〜５のアルキル基である。Ｍ^＋は第一のアンモニウムカチオンである。］

[Wherein, R and W ⁰ are the same as defined above. Q ²¹ is a single bond or a divalent linking group. Q ²² is a divalent linking group. Q ²³ is a group containing —O—, —CH ₂ —O—, or —C (═O) —O—. R ^q1 is a fluorine atom or a fluorinated alkyl group. R ^ar is a divalent aromatic group which may have a substituent. R ⁿ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. M ⁺ is the first ammonium cation. ]

［式中、Ｒ、Ｒ^ｆ１、Ｒ^ｆ２、ｐ０は前記同様である。Ｒ^ｎは水素原子又は炭素数１〜５のアルキル基である。Ｑ^２１はそれぞれ独立に単結合又は２価の連結基である。Ｑ^２２は２価の連結基である。Ｑ^２３は−Ｏ−、−ＣＨ_２−Ｏ−、又は−Ｃ（＝Ｏ）−Ｏ−を含有する基である。Ｒ^ｑ１はフッ素原子又はフッ素化アルキル基である。Ｍ^＋は第一のアンモニウムカチオンである。］

[Wherein, R, R ^f1 , R ^f2 and p0 are the same as above. R ⁿ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Q ²¹ is each independently a single bond or a divalent linking group. Q ²² is a divalent linking group. Q ²³ is a group containing —O—, —CH ₂ —O—, or —C (═O) —O—. R ^q1 is a fluorine atom or a fluorinated alkyl group. M ⁺ is the first ammonium cation. ]

［式中、Ｒ、Ｑ^２１〜Ｑ^２３、Ｚ^３〜Ｚ^５、Ｒ^６２〜Ｒ^６３、Ｒ^ｎ、Ｒ^ｑ１は前記同様である。ｎ６０は０〜３の整数である。Ｍ^＋は第一のアンモニウムカチオンである。］

[Wherein, R, Q ^{21 to} Q ²³ , Z ^{3 to} Z ⁵ , R ^{62 to} R ⁶³ , R ⁿ and R ^q1 are the same as described above. n60 is an integer of 0-3. M ⁺ is the first ammonium cation. ]

［式中、Ｒ、Ｚ^１〜Ｚ^２、Ｒ^ｎは前記と同様であり、Ｑ^２４、Ｑ^２５はそれぞれ独立に単結合又は２価の連結基である。Ｍ^＋は第一のアンモニウムカチオンである。］

[Wherein, R, Z ^{1 to} Z ² and R ⁿ are the same as defined above, and Q ²⁴ and Q ²⁵ each independently represent a single bond or a divalent linking group. M ⁺ is the first ammonium cation. ]

［式中、Ｒ、Ｒ^ｎは前記と同様であり、Ｑ^２６〜Ｑ^２８はそれぞれ独立に単結合又は２価の連結基である。ｎ３０は０〜３の整数である。Ｍ^＋は第一のアンモニウムカチオンである。］

[Wherein, R and R ⁿ are as defined above, and Q ^{26 to} Q ²⁸ each independently represent a single bond or a divalent linking group. n30 is an integer of 0-3. M ⁺ is the first ammonium cation. ]

In formulas (an11) to (an14), W ⁰ and R ^q1 are the same as described above.
R ^ar is a divalent aromatic group which may have a substituent. Examples of the divalent aromatic group include the same aromatic groups as those described as the divalent hydrocarbon group in the description of the divalent linking group at W ⁰ in the general formula (an1). Especially, the phenylene group which may have a substituent, or the naphthylene group which may have a substituent is preferable.

Q ²¹ is a single bond or a divalent linking group. Examples of the divalent linking group for Q ²¹ include the same divalent linking groups as those described above for Q ² . Among these, Q ²¹ is preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a divalent linking group containing a hetero atom; A branched alkylene group, a combination of a linear or branched alkylene group and a divalent linking group containing a heteroatom, a cyclic aliphatic hydrocarbon group and a divalent linking group containing a heteroatom. A combination or a combination of an aromatic hydrocarbon group and a divalent linking group containing a hetero atom is more preferable; a linear or branched alkylene group, a linear or branched alkylene group and an ester bond [- A combination of C (═O) —O—] with a divalent alicyclic hydrocarbon group and an ester bond [—C (═O) —O—] is particularly preferred; linear or branched An alkylene group of A combination of a branched alkylene group and an ester bond [—C (═O) —O—] is most preferred.

Wherein (AN12), Q ²² represents a divalent linking group, wherein the same as the divalent linking group for Q ^2. Among them, straight-chain or branched mentioned in W ⁰ An alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent aromatic hydrocarbon group is preferable, a linear alkylene group is particularly preferable, and a methylene group or an ethylene group is most preferable.
Wherein (an12), ^{R n} represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. As a C1-C5 alkyl group, the same thing as the C1-C5 alkyl group of said R is mentioned. Of these, R ⁿ is preferably a hydrogen atom or a methyl group.

In formula (an13), Q ²³ represents a group containing —O—, —CH ₂ —O—, or —C (═O) —O—.
Q ²³ is specifically a group consisting of —O—, —CH ₂ —O—, or —C (═O) —O—; —O—, —CH ₂ —O— or —C (═O). And a group composed of —O— and a divalent hydrocarbon group which may have a substituent.
As such a substituted or divalent be hydrocarbon groups include the same bivalent bivalent which may have a substituent mentioned in linking group of the hydrocarbon group in the Q ² Is mentioned.
Q ²³ is preferably a group consisting of —C (═O) —O— and a divalent hydrocarbon group which may have a substituent, and —C (═O) —O— and aliphatic carbonization. A group consisting of a hydrogen group is more preferred, and a group consisting of —C (═O) —O— and a linear or branched alkylene group is more preferred.
Specific examples suitable for Q ^23, in particular, a group represented by the following general formula ^(Q 23 -1).

［式（Ｑ^２３−１）中、Ｒ^ｑ２及びＲ^ｑ３はそれぞれ独立に水素原子、アルキル基又はフッ素化アルキル基であり、互いに結合して環を形成していてもよい。］

[In the formula (Q ²³ -1), R ^q2 and R ^q3 each independently represent a hydrogen atom, an alkyl group, or a fluorinated alkyl group, and may be bonded to each other to form a ring. ]

In the formula (Q ²³ -1), the alkyl group in R ^q2 and R ^q3 may be linear, branched or cyclic, and is preferably linear or branched.
In the case of a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 5, more preferably an ethyl group or a methyl group, and particularly preferably an ethyl group.
In the case of a cyclic alkyl group, the number of carbon atoms is preferably 4 to 15, more preferably 4 to 12, and most preferably 5 to 10. Specific examples include monocycloalkanes; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. It is done. Of these, a group in which one or more hydrogen atoms have been removed from adamantane is preferable.

The fluorinated alkyl group for R ^q2 and R ^q3 is a group in which part or all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms.
In the fluorinated alkyl group, the alkyl group not substituted with a fluorine atom may be linear, branched or cyclic, and the same as the above-mentioned “alkyl group in R ^q2 and R ^q3 ”. Can be mentioned.

R ^q2 and R ^q3 may be bonded to each other to form a ring, and the ring formed by R ^q2 and R ^q3 and the carbon atom to which they are bonded includes a monocyclo group in the cyclic alkyl group. The thing remove | excluding two hydrogen atoms from alkane or polycycloalkane can be illustrated, It is preferable that it is a 4-10 membered ring, and it is more preferable that it is a 5-7 membered ring.

Among the above, R ^q2 and R ^q3 are preferably a hydrogen atom or an alkyl group.

In formula (an13), R ^q1 represents a fluorine atom or a fluorinated alkyl group.
In the fluorinated alkyl group for R ^q1 , the alkyl group not substituted with a fluorine atom may be linear, branched or cyclic.
In the case of a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and particularly preferably 1 to 2. .
In the case of a cyclic alkyl group, the number of carbon atoms is preferably 4 to 15, more preferably 4 to 12, and still more preferably 5 to 10. Specific examples include monocycloalkanes; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .
In the fluorinated alkyl group, the ratio of the number of fluorine atoms to the total number of fluorine atoms and hydrogen atoms contained in the fluorinated alkyl group (fluorination rate (%)) is preferably 30 to 100%. 50 to 100% is more preferable. The higher the fluorination rate, the higher the hydrophobicity of the resist film.
Among the above, R ^q1 is preferably a fluorine atom.
Wherein ^{(an11-1) ~ (an13-1),} R, Q 21 ~Q 23, R f1, R f2, p0, R n are as defined above.

Wherein ^{(an21) ~ (an25),} R, Q 21 ~Q 23, Z 3 ~Z 5, R 62 ~R 63, R n, R q1 are as defined above.
In formula (an24), n60 is an integer of 0 to 3, and is preferably 0 or 1.

In formulas (an31) to (an32), R, Z ^{1 to} Z ² and R ⁿ are the same as described above, and Q ²⁴ and Q ²⁵ are each independently a single bond or a divalent linking group.
Examples of the divalent linking group for Q ²⁴ and Q ²⁵ include the same divalent linking groups as those described above for Q ² . As described above, if ^{Z 1} is a single ^bond, end which binds to ^{Z 1} of Q ^{24, Q 25} is -C (= O) - is not preferred. The divalent linking group for Q ²⁴ and Q ²⁵ is particularly preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent linking group containing a hetero atom. Among these, a linear or branched alkylene group and a cyclic aliphatic hydrocarbon group are preferable, and a linear alkylene group and a cyclic aliphatic hydrocarbon group are more preferable.

Wherein (an41) ~ (an44), R, R n are as defined ^above, Q 26 ^{to Q 28} represents a single bond or a divalent linking group independently. Q ²⁶ to Q ²⁸ are the same as the ^{Q 24, Q 25.}
In formula (an44), n30 is an integer of 0 to 3, and is preferably 0 or 1.

Specific examples of the monomer (G) are shown below. In the following formulas, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group, and M ⁺ (first ammonium cation) is the same as described above.

In the first precursor polymer, the structure of “the structural unit containing the first ammonium cation and the anionic group that generates an acid upon exposure”, the types of other structural units introduced as necessary, The content ratio of each constituent unit; the mass average molecular weight, the degree of dispersion, and the like may be appropriately determined in consideration of the desired copolymer composition ratio, required characteristics, and the like.
The first precursor polymer is obtained by a method of polymerizing monomers (including monomer (G)) for inducing each of the constituent units forming the first precursor polymer by a known radical polymerization or the like described below [ It can be obtained by the method of performing the operation of the step of obtaining one precursor polymer.
Further, the during the _{polymerization, HS-CH 2 -CH 2 -CH} 2 -C (CF 3) By use of a chain transfer agent such as 2 -OH, -C terminated _{(CF 3)} 2 -OH group May be introduced. Thus, when a copolymer into which a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is used in a resist composition, development defects are reduced or LER (Line Edge Roughness: This is effective in reducing the unevenness of the line side wall.

(Reaction of first precursor polymer with amine)
In the amine reaction step, for example, the first precursor polymer and the amine are reacted in an organic solvent, whereby the first ammonium cation in the first precursor polymer is conjugated with the amine conjugate acid (second acid). A second precursor polymer having a second ammonium cation.
The amount of the first precursor polymer and amine used is appropriately determined in consideration of the amount of the first ammonium cation in the first precursor polymer.
0-50 degreeC is preferable and, as for reaction temperature, 10-30 degreeC is more preferable.
The reaction time varies depending on the reactivity of the first precursor polymer and amine, the reaction temperature, and the like, but is preferably 5 minutes or more and 24 hours or less, more preferably 10 to 120 minutes, and even more preferably 10 to 60 minutes.
The organic solvent only needs to contain at least a component capable of dissolving both the first precursor polymer and the amine. Among them, a good solvent that dissolves the obtained second precursor polymer, and the second precursor It is preferable to use in combination with a poor solvent that does not dissolve the body polymer.
Examples of the good solvent include polar solvents such as acetonitrile, dimethyl sulfoxide, N, N-dimethylformamide, and methanol.
Examples of the poor solvent include hydrocarbon solvents such as n-heptane and n-hexane, and ether solvents such as tert-butyl methyl ether and diisopropyl ether.
After reacting the first precursor polymer with the amine, the reaction solution (the good solvent side when a good solvent and a poor solvent are combined) is used, for example, a large amount of organic solvent (diisopropanol, heptane, methanol, etc.) The second precursor polymer can be obtained by precipitating the polymer by dropping it into the solution and filtering it out.

[Salt exchange process]
In the salt exchange step, the second precursor polymer obtained in the amine reaction step and the sulfonium cation or iodonium cation (final sulfonium or iodonium cation) are subjected to salt exchange.

(Final sulfonium or iodonium cation)
The final sulfonium or iodonium cation used in the salt exchange step is a cation having higher hydrophobicity than the second ammonium cation. The salt exchange in the salt exchange step is exchange from a cation with low hydrophobicity to a cation with high hydrophobicity so that the salt exchange proceeds well and a polymer compound having a desired final sulfonium or iodonium cation (final purpose) Product) can be manufactured.

  Examples of the final sulfonium or iodonium cation include cations represented by the following general formulas (ca-1) to (ca-3), respectively.

［式中、Ｒ^２０１〜Ｒ^２０７およびＲ^２１０は、それぞれ独立に置換基を有していてもよいアリール基、アルキル基またはアルケニル基を表し、Ｒ^２０１〜Ｒ^２０３のいずれか２つ、Ｒ^２０６〜Ｒ^２０７は相互に結合して式中のイオウ原子と共に環を形成してもよい。Ｒ^２０８〜Ｒ^２０９はそれぞれ独立に水素原子または炭素数１〜５のアルキル基を表し、Ｌ^２０１は−Ｃ（＝Ｏ）−または−Ｃ（＝Ｏ）−Ｏ―を表す。］

[Wherein, R ^{201 to} R ²⁰⁷ and R ²¹⁰ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and any two of R ^{201 to} R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ may form a ring with the sulfur atom bonded to each other. R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and L ²⁰¹ represents —C (═O) — or —C (═O) —O—. ]

In the method for producing a polymer compound of the present invention, the general formula (ca-1) or the general formula (ca-2) has a small number of aromatic rings in R ^{201 to} R ²⁰⁵ (preferably two or less, more preferably 0 or 1) It is particularly useful as a method for producing a polymer compound.

As the aryl group in R ²⁰¹ to R ²⁰⁷ and ^{R 210,} include unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, a naphthyl group.

The alkyl group in R ^{201 to} R ²⁰⁷ and R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ^{201 to} R ²⁰⁷ and R ²¹⁰ preferably has 2 to 10 carbon atoms.

Examples of the substituent that R ^{201 to} R ²⁰⁷ and R ²¹⁰ may have include an alkyl group, a halogen atom (preferably a fluorine atom), a halogenated alkyl group, an oxo group (═O), a cyano group, and an amino group. Groups, aryl groups, and groups represented by the following formulas (ca-r-1) to (ca-r-7).

［式中、Ｒ’^２０１はそれぞれ独立に水素原子又は炭素数１〜３０の炭化水素基である。］

[Wherein, R ′ ²⁰¹ is independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. ]

The hydrocarbon group of R ′ ^{201 is the same as} the cyclic group which may have a substituent of R ¹⁰¹ described later and the chain alkyl group or alkenyl group which may have a substituent.
Any two of R ^{201 to} R ²⁰³ , R ^{206 to} R ²⁰⁷ , when bonded to each other to form a ring together with the sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom or a nitrogen atom, _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), such as You may couple | bond through a functional group. As the ring to be formed, one ring containing a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring, including the sulfur atom. preferable. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

  Specific examples of suitable cations of formula (ca-1) include cations represented by the following formulas.

［式中、ｇ１、ｇ２、ｇ３は繰返し数を示し、ｇ１は１〜５の整数であり、ｇ２は０〜２０の整数であり、ｇ３は０〜２０の整数である。］

[Wherein, g1, g2, and g3 represent the number of repetitions, g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20. ]

［式中、Ｒｄは水素原子又は置換基であって、置換基としては前記Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜Ｒ^２１２が有していてもよい置換基として挙げたものと同様である。］

[Wherein, Rd is a hydrogen atom or a substituent, and the substituent is the same as the substituent that may be possessed by R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² . ]

  Specific examples of suitable cations of formula (ca-3) include cations represented by the following formulas.

  The final sulfonium or iodonium cation preferably has a retention time (retention time) of 1.5 minutes or more, more preferably 2 minutes or more, measured under the specific conditions of the HPLC method described above. The upper limit is not particularly limited but is preferably 60 minutes or less. If the retention time is equal to or more than the preferred lower limit, the salt exchange reaction between the second precursor polymer and the sulfonium or iodonium cation tends to proceed well.

Regarding the final sulfonium or iodonium cation exemplified above, the retention times (retention times) measured under the specific conditions of the HPLC method are as follows.
Examples of the retention time (holding time) in the range of 2.6 minutes or less include, for example, the above formulas (ca-1-38) to (ca-1-42) and (ca-1-63), respectively. Among the cations represented by the formula (ca-1-53), those in which Rd is small such as a hydrogen atom, a methyl group or an alkoxy group, or a polar group such as a hydroxyl group or a carboxy group; And cations represented by (ca-3-1). For example, the retention time of the cation represented by the formula (ca-1-38) is 2.3 minutes, and the retention time of the cation represented by the formula (ca-1-63) is 2.6 minutes.
Examples of the retention time (holding time) in the range of more than 2.6 minutes to 4 minutes or less include, for example, the above formulas (ca-1-1), (ca-1-2), (ca-1- 17) to (ca-1-25), (ca-1-28), (ca-1-29); in the cations represented by the above formulas (ca-1-30) to (ca-1-31) g2 and g3 having a small number of repetitions (about 0 to 2); (ca-1-32), (ca-1-34), (ca-1-36), (ca-1-43) to (ca -1-46), (ca-1-50) to (ca-1-52), (ca-1-54), (ca-1-58) to (ca-1-60), and cations represented by ca-1-53), respectively. For example, the retention time of the cation represented by the formula (ca-1-1) is 2.7 minutes, and the retention time of the cation represented by the formula (ca-1-2) is 3.1 minutes.
Examples of the retention time (retention time) exceeding 4 minutes include, for example, the above formulas (ca-1-3) to (ca-1-16), (ca-1-21), (ca-1- 26), (ca-1-27), (ca-1-29); large number of repetitions of g2 and g3 in the cations represented by the formulas (ca-1-30) to (ca-1-31) (3 or more); (ca-1-33), (ca-1-35), (ca-1-37), (ca-1-47) to (ca-1-49), (ca-1 -55) to (ca-1-57), (ca-1-61), (ca-1-62), and cations represented by (ca-3-2), respectively. For example, the retention time of the cation (when g1 is 1) represented by the formula (ca-1-29) is 6.7 minutes.
A cation having a highly hydrophobic substituent tends to have a long retention time, and a cation having a hydrophilic group such as a polar group tends to have a short retention time.

  In addition, the second ammonium cation and the final sulfonium or iodonium cation need to have some difference in retention time in the measurement by the HPLC method described above (retention time of final sulfonium or iodonium cation). Is divided by (retention time of the second ammonium cation) to be greater than 1, preferably 1.005 or more, and more preferably 1.01 or more. By setting it to 1.005 or more, salt exchange proceeds easily. Since the second ammonium cation is highly hydrophilic and the retention time is basically shortened, salt exchange proceeds easily if there is a slight difference from the final sulfonium or iodonium cation.

(Salt exchange between second precursor polymer and sulfonium cation or iodonium cation)
The salt exchange between the second precursor polymer and the sulfonium cation or iodonium cation (final sulfonium or iodonium cation) is preferably performed in a two-layer system of an organic solvent and water.
In the salt exchange step, for example, the second precursor polymer and the compound having the final sulfonium or iodonium cation (salt exchange compound) are mixed in a mixed solvent of an organic solvent and water. (A polymer compound having a structural unit that decomposes upon exposure to generate an acid) is obtained.

The salt exchange compound used in the salt exchange step is a compound having a final sulfonium or iodonium cation, and is obtained by salt exchange between the final sulfonium or iodonium cation of the salt exchange compound and the second precursor polymer. Salt exchange is possible. That is, the final sulfonium or iodonium cation of the salt exchange compound becomes the cation of the polymer compound produced by the production method of the present invention.
The compound for salt exchange is preferably a compound composed of a cation moiety composed of a final sulfonium or iodonium cation and an anion moiety composed of a non-nucleophilic ion.
Examples of non-nucleophilic ions include halogen ions such as bromine ions and chlorine ions; ions that can be acids with lower acidity than the second precursor polymer, BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ^- or ClO ₄ ^- and the like. The ion that can be an acid having a lower acidity than the second precursor polymer is not particularly limited and can be appropriately determined according to the type of monomer used in the second precursor polymer. For example, p-toluenesulfone Examples thereof include sulfonate ions such as acid ions, methanesulfonate ions, and benzenesulfonate ions.

  The organic solvent constituting the mixed solvent with water may be any one that can be separated from water and dissolve the second precursor polymer, such as cyclohexanone, methyl ethyl ketone, propylene glycol monomethyl ether acetate, tetrahydrofuran, dichloromethane, , 2-dichloroethane, ethyl acetate, propionitrile, or a mixed solvent thereof can be used.

About 0-50 degreeC is preferable and, as for the temperature conditions at the time of performing salt exchange, about 10-30 degreeC is more preferable.
The mixing time of the second precursor polymer and the compound for salt exchange varies depending on the reactivity and temperature conditions of the second precursor polymer and the compound for salt exchange, but it is 0.5 minutes or more and 24 hours or less. Is preferably 5 minutes or more and 12 hours or less, and more preferably 10 to 60 minutes.
The amount of the salt exchange compound used in such salt exchange is preferably about 1 to 10 moles with respect to 1 mole of the monomer for deriving the structural unit having the second ammonium cation in the second precursor polymer, and 1 to 5 moles. The degree is more preferable.
In addition, the substance amount of the monomer for deriving the structural unit having the second ammonium cation in the second precursor polymer is a copolymer composition ratio determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) ( It can be determined by conversion from the ratio (molar ratio) of each structural unit in the structural formula.

After completion of the salt exchange reaction between the second precursor polymer and the salt exchange compound, it is preferable to isolate and purify the polymer compound (final target product) in the reaction solution.
For isolation and purification, conventionally known methods can be used. For example, concentration, water washing, organic solvent washing, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more. They can be used in combination.

  The polymer compound produced by the production method according to the present invention can be suitably used as a base component of a resist composition. When the polymer compound is used as a base material component of a resist composition, the preferred content of each structural unit, mass average molecular weight, dispersity, etc. in the polymer compound will be described in the description of “resist composition” below. Will be described in detail.

[Step of obtaining first precursor polymer]
In the method for producing a polymer compound of the present invention, in addition to the amine reaction step and the salt exchange step, a sulfonium cation or an iodonium cation (in the present specification, these cations are referred to as “second sulfonium or iodonium cation”). And a step of obtaining a first precursor polymer by salt exchange between the third precursor polymer having) and the first ammonium cation having higher hydrophobicity than the second sulfonium or iodonium cation. preferable.
In the step of obtaining the first precursor polymer, for example, the first precursor polymer and the salt having the first ammonium cation are mixed in a mixed solvent of an organic solvent and water, etc. The precursor polymer is obtained.

(Salt having first ammonium cation)
The first ammonium cation is the same as the first ammonium cation in the first precursor polymer described above, and is more hydrophobic than the second sulfonium or iodonium cation.
The salt having the first ammonium cation is capable of salt exchange between the first ammonium cation of the salt and the third precursor polymer by salt exchange. That is, the first ammonium cation possessed by the salt becomes the cation possessed by the first precursor polymer.
The salt having the first ammonium cation is preferably a compound composed of a cation moiety composed of the first ammonium cation and an anion moiety composed of a non-nucleophilic ion.
Examples of the non-nucleophilic ion include those similar to the non-nucleophilic ion in the salt exchange compound.

(Third precursor polymer)
The third precursor polymer is one having a second sulfonium or iodonium cation.
The second sulfonium or iodonium cation is a cation that is less hydrophobic than the first ammonium cation. The salt exchange in the step of obtaining the first precursor polymer is an exchange from a low hydrophobic cation to a highly hydrophobic cation, so that the salt exchange proceeds well and has the desired first ammonium cation. A first precursor polymer can be produced.

  The second sulfonium or iodonium cation preferably has a retention time (retention time) of 2 to 10 minutes, more preferably 2.5 to 6 minutes, measured under the specific conditions of the HPLC method described above. Preferably, more than 2.6 minutes and not more than 5 minutes is more preferable. When the holding time is equal to or more than the preferred lower limit, the polymer is excellent in solubility in an organic solvent, and the synthesis of the third precursor polymer is facilitated. On the other hand, if the retention time is less than or equal to the preferred upper limit value, the salt exchange reaction in producing the first precursor polymer proceeds easily.

Specific examples of the second sulfonium or iodonium cation include those similar to the cations exemplified for the final sulfonium or iodonium cation described above. That's fine.
Preferably, it is a cation having the above retention time (retention time) in the range of more than 2.6 minutes, particularly preferably the formula (ca-1-1), (ca-1-2) or (ca-1-). 58) to (ca-1-62).

  In addition, the second sulfonium or iodonium cation and the first ammonium cation need to have a certain difference in retention time in the measurement by the HPLC method described above. Time) divided by (retention time of the second sulfonium or iodonium cation) is greater than 1, preferably 1.1 or more, more preferably 1.2 or more preferable. By setting it to 1.1 or more, salt exchange proceeds easily.

  The organic solvent constituting the mixed solvent with water may be any one that can be separated from water and can dissolve the second precursor polymer. Cyclohexanone, methyl ethyl ketone, propylene glycol monomethyl ether acetate, tetrahydrofuran, dichloromethane, 1, 2-dichloroethane, ethyl acetate, propionitrile, or a mixed solvent thereof can be used.

In the step of obtaining the first precursor polymer, the temperature condition and the mixing time for salt exchange are the same as the temperature condition and the mixing time in the salt exchange step.
The amount of the salt having the first ammonium cation is preferably about 1 to 5 mol relative to 1 mol of the monomer for deriving the structural unit having the second sulfonium or iodonium cation in the third precursor polymer.

After completion of the salt exchange reaction in the step of obtaining the first precursor polymer, it is preferable to isolate and purify the polymer compound (first precursor polymer) in the reaction solution.
For isolation and purification, conventionally known methods can be used. For example, concentration, water washing, organic solvent washing, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more. They can be used in combination.

Examples of the third precursor polymer include those obtained by replacing the first ammonium cation in the first precursor polymer with a second sulfonium or iodonium cation.
The third precursor polymer is derived from a monomer in which the first ammonium cation in the monomer (G) is replaced with the second sulfonium or iodonium cation (hereinafter, this monomer is referred to as “monomer (G ′)”). Those having a structural unit are preferred.
And like said 1st precursor polymer, it is preferable that the 3rd precursor polymer has the below-mentioned structural unit (a1) in addition to the structural unit induced | guided | derived from a monomer (G '), and other structure As a unit, you may have the below-mentioned structural unit (a2), (a3), (a4), etc.
The third precursor polymer can be obtained by a method of polymerizing a monomer (including monomer (G ′)) for deriving each structural unit forming the third precursor polymer by a known radical polymerization or the like. Further, the during the _{polymerization, HS-CH 2 -CH 2 -CH} 2 -C (CF 3) By use of a chain transfer agent such as 2 -OH, -C terminated _{(CF 3)} 2 -OH group May be introduced.

The polymer compound produced by the method for producing a polymer compound according to the present invention has a structural unit that decomposes upon exposure to generate an acid (hereinafter, this structural unit is also referred to as “structural unit (a0)”). It is.
In the production of the polymer compound having the structural unit (a0), the inventors of the present invention used an anion group that generates an acid upon exposure and a cation (final sulfonium or iodonium having a lower hydrophobicity than conventional triphenylsulfonium cations and the like. When a monomer having a cation) or a compound for salt exchange having a final sulfonium or iodonium cation is used as a raw material, it has been confirmed that synthesis of a polymer compound is difficult by known radical polymerization, salt exchange or the like. . This is presumed to be due to cation instability in the monomer or salt exchange compound.
Therefore, in the production method according to the present invention, instead of the cation (final sulfonium or iodonium cation) that the structural unit (a0) should have, a (structurally) stable and highly hydrophobic cation (first ammonium) A precursor polymer having a cation) (first precursor polymer) is used.
Then, utilizing the difference in acid dissociation constant (pKa), that is, using an amine having a pKa larger than that of the first ammonium cation, and reacting the amine with the first precursor polymer, the final sulfonium or iodonium A second precursor polymer having a conjugate acid (second ammonium cation) that is less hydrophobic than the cation is synthesized. Thereby, the salt exchange in the next step can be changed from a low hydrophobic cation to a high hydrophobic cation. As a result, since salt exchange proceeds satisfactorily, a polymer compound having a desired structural unit (a0) can be produced.
According to this production method, it is possible to easily produce a polymer compound having a structural unit that is difficult to be directly synthesized and decomposes by exposure to generate an acid.
Moreover, according to this production method, various cations can be introduced into the polymer compound. Thereby, the freedom degree of selection of the cation seed | species in a high molecular compound increases. In addition, since the composition of the resist composition using the polymer compound can be optimized, it can contribute to the improvement of lithography characteristics.

≪Resist composition≫
The resist composition of the present invention is a polymer compound produced by the method for producing a polymer compound of the present invention, that is, a polymer having a structural unit (structural unit (a0)) that decomposes upon exposure to generate an acid. A compound.
The resist composition of the present invention preferably contains a base component (A) (hereinafter referred to as “component (A)”) whose solubility in a developer is changed by the action of an acid. When a resist film is formed using such a resist composition and the resist film is selectively exposed, an acid is generated from the structural unit (a0) in the exposed portion, and the action of the acid (A ) While the solubility of the component in the developer changes, the solubility of the component (A) in the developer does not change in the unexposed area, so the solubility in the developer between the exposed and unexposed areas There is a difference. For this reason, when the resist film is developed, when the resist composition is positive, the exposed portion is dissolved and removed to form a positive resist pattern. When the resist composition is negative, the unexposed portion is formed. A negative resist pattern is formed by dissolution and removal.
In this specification, a resist composition in which an exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and an unexposed portion is dissolved and removed to form a negative resist pattern. Is referred to as a negative resist composition.
The resist composition of the present invention may be a positive resist composition or a negative resist composition.
In addition, the resist composition of the present invention may be used for an alkali development process using an alkali developer for development processing at the time of forming a resist pattern. It may be for the solvent development process used.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
“Organic compounds having a molecular weight of 500 or more” used as the base component are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the “low molecular compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, those having a molecular weight of 1000 or more are usually used. In the present specification and claims, the term “resin” refers to a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used.
Component (A) may have increased solubility in a developer due to the action of an acid, or may decrease solubility in a developer due to the action of an acid.

When the resist composition of the present invention is a resist composition that forms a negative resist pattern in an alkali development process (or forms a positive resist pattern in a solvent development process), the component (A) is preferably In addition, a base material component (hereinafter sometimes referred to as “(A0 ′) component”) soluble in an alkali developer is used, and a crosslinking agent component is further blended. As the component (A0 ′), a resin (alkali-soluble resin) is usually used. In such a resist composition, when an acid is generated from the structural unit (a0) by exposure, the acid acts to cause crosslinking between the component (A0 ′) and the crosslinking agent component, resulting in solubility in an alkaline developer. Decreases (the solubility in an organic developer increases). Therefore, in the formation of a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed, the exposed portion is hardly soluble in an alkali developer (to an organic developer). On the other hand, the unexposed area remains soluble (almost insoluble in the organic developer) while remaining undissolved in the alkali developer, so that a negative resist pattern can be formed by developing with an alkali developer. . At this time, if an organic developer is used as the developer, a positive resist pattern can be formed.
As the component (A0 ′), a known resin can be used as a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”).
Examples of the alkali-soluble resin include α- (hydroxyalkyl) acrylic acid or α- (hydroxyalkyl) acrylic acid alkyl ester (preferably having 1 to 5 carbon atoms) disclosed in, for example, JP-A-2000-206694. Resin having a unit derived from at least one selected from alkyl ester); disclosed in US Pat. No. 6,949,325, an atom other than a hydrogen atom or a substituent is bonded to the α-position carbon atom having a sulfonamide group Acrylic resin or polycycloolefin resin which may be used; containing a fluorinated alcohol disclosed in US Pat. An atom other than a hydrogen atom or a substituent may be bonded to the carbon atom. Acrylic resin; disclosed in Japanese 2006-259582 discloses, polycycloolefin resins having fluorinated alcohol, with minimal swelling can formation of a satisfactory resist pattern.
The “α- (hydroxyalkyl) acrylic acid” is an α-position where a carboxy group is bonded among acrylic acids in which an atom other than a hydrogen atom or a substituent may be bonded to a carbon atom at the α-position. Of acrylic acid in which a hydrogen atom is bonded to the carbon atom and α-hydroxyalkyl acrylic acid in which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded to the α-position carbon atom. Indicates one or both.
As the crosslinking agent component, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine crosslinking agent, or the like because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent component is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a resist composition that forms a positive pattern in an alkali development process and forms a negative pattern in a solvent development process, the component (A) is preferably an action of an acid. A substrate component (A0) (hereinafter referred to as “(A0) component”) having an increased polarity is used. Since the polarity of the component (A0) changes before and after exposure, good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
That is, when the alkali development process is applied, the component (A0) is hardly soluble in an alkali developer before exposure, and when acid is generated from the structural unit (a0) by exposure, the polarity of the component is reduced by the action of the acid. Increases the solubility in an alkaline developer. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion changes from slightly soluble to soluble in an alkaline developer. Since the unexposed portion remains hardly soluble in alkali and does not change, a positive pattern can be formed by alkali development.
On the other hand, when applying the solvent development process, the component (A0) is highly soluble in an organic developer before exposure, and when an acid is generated from the structural unit (a0) by exposure, The polarity becomes higher and the solubility in an organic developer decreases. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the resist composition on the support is selectively exposed, the exposed portion changes from soluble to poorly soluble in an organic developer. On the other hand, since the unexposed portion remains soluble and does not change, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, and a negative pattern can be formed.

In the present invention, the component (A) is preferably the component (A0). That is, the resist composition of the present invention is preferably a chemically amplified resist composition that becomes positive in the alkali development process and negative in the solvent development process.
The component (A0) may be a resin component whose polarity is increased by the action of an acid, a low molecular compound component whose polarity is increased by the action of an acid, or a mixture thereof. .
The component (A0) is preferably a resin component that increases in polarity by the action of an acid. In particular, the polymer compound (A1) that generates an acid by exposure and increases in polarity by the action of an acid (hereinafter referred to as “A0”) What contains "(A1) component") is preferable.

[(A1) component]
Specifically, the component (A1) is a high component having a structural unit (a0) that decomposes upon exposure to generate an acid and a structural unit (a1) that includes an acid-decomposable group that increases in polarity by the action of an acid. A molecular compound is preferred, and a polymer compound produced by the polymer compound production method of the first aspect is particularly preferred.

(Structural unit (a0))
The structural unit (a0) is a structural unit that decomposes upon exposure to generate an acid.
As the structural unit (a0), a structural unit containing the above-mentioned final sulfonium or iodonium cation and the anionic group that generates an acid upon exposure can be mentioned. Specifically, the structural unit can be represented by the following general formula (a0-1). The structural unit is preferred.

［式中、Ｒ、Ｑ^２、Ａ⁻は前記同様であり、Ｍ’^＋は上述した第二のスルホニウム又はヨードニウムカチオンである。］

[Wherein, R, Q ² and A ⁻ are the same as defined above, and M ′ ⁺ represents the second sulfonium or iodonium cation described above. ]

  Specifically, as the structural unit (a0), compounds represented by the above formulas (an11) to (an14), (an21) to (an25), (an31) to (an32), and (an41) to (an44), respectively Particularly preferred is a structural unit derived from at least one compound selected from the group consisting of: wherein the cation moiety is the final sulfonium or iodonium cation.

In the component (A1), as the structural unit (a0), one type of structural unit may be used, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a0) is preferably 1 to 40 mol%, more preferably 1 to 35 mol%, based on the total of all the structural units constituting the component (A1). 3-30 mol% is more preferable.
When the proportion of the structural unit (a0) is not less than the lower limit of the above range, a pattern can be easily obtained when the resist composition is obtained, and the lithography properties are further improved. On the other hand, by being below the upper limit value, it is possible to balance with other structural units.

(Structural unit (a1))
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
The “acid-decomposable group” is an acid-decomposable group that can cleave at least part of bonds in the structure of the acid-decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include a group in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of OH in an OH-containing polar group is protected with an acid-dissociable group).
The “acid-dissociable group” is a group having an acid-dissociable property capable of cleaving at least a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid. The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility in the developer changes relatively. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases. .

The acid-dissociable group is not particularly limited, and those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists can be used. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable group such as an alkoxyalkyl group is widely known.
Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (═O The structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of) -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom to form a carboxy group.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable group” for convenience.

Examples of the tertiary alkyl ester type acid dissociable group include an aliphatic branched acid dissociable group and an acid dissociable group containing an aliphatic cyclic group.
Here, “aliphatic branched” means having a branched structure having no aromaticity. The structure of the “aliphatic branched acid dissociable group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
Examples of the aliphatic branched acid dissociable group include a group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). ^Wherein, R 71 ^{to R 73} each independently represents a linear alkyl group of 1 to 5 carbon atoms. The group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) preferably has 4 to 8 carbon atoms, specifically a tert-butyl group or a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like. A tert-butyl group is particularly preferable.

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The aliphatic cyclic group in the “acid-dissociable group containing an aliphatic cyclic group” may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
The basic ring structure excluding the substituent of the aliphatic cyclic group is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The hydrocarbon group may be either saturated or unsaturated, but is usually preferably saturated.
The aliphatic cyclic group may be monocyclic or polycyclic.
Examples of the aliphatic cyclic group include one or more hydrogens from a monocycloalkane which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group. A group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, or tetracycloalkane; More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. An alicyclic hydrocarbon group such as a group excluding a hydrogen atom is exemplified. Moreover, a part of carbon atoms constituting the ring of these alicyclic hydrocarbon groups may be substituted with an ether group (—O—).

Examples of the acid dissociable group containing an aliphatic cyclic group include:
(I) On the ring skeleton of the monovalent aliphatic cyclic group, the substituent ( An atom or group other than a hydrogen atom) to form a tertiary carbon atom;
(Ii) a group having a monovalent aliphatic cyclic group and a branched alkylene having a tertiary carbon atom bonded thereto.
In the group (i), examples of the substituent bonded to the carbon atom bonded to the atom adjacent to the acid dissociable group on the ring skeleton of the aliphatic cyclic group include an alkyl group. Examples of the alkyl group include those similar to R ¹⁴ in formulas (1-1) to (1-9) described later.
Specific examples of the group (i) include groups represented by the following general formulas (1-1) to (1-9).
Specific examples of the group (ii) include groups represented by the following general formulas (2-1) to (2-6).

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

[Wherein, R ¹⁴ represents an alkyl group, and g represents an integer of 0 to 8. ]

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group. ]

In formulas (1-1) to (1-9), the alkyl group of R ¹⁴ may be linear, branched or cyclic, and is preferably linear or branched.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group and the like, and isopropyl group is most preferable.
Examples of the cyclic alkyl group include those similar to the above aliphatic cyclic group.
g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and still more preferably 1 or 2.
In formulas (2-1) to (2-6), examples of the alkyl group for R ^{15 to} R ¹⁶ include the same alkyl groups as those described above for R ¹⁴ .
In the formulas (1-1) to (1-9) and (2-1) to (2-6), a part of the carbon atoms constituting the ring is substituted with an etheric oxygen atom (—O—). May be.
In formulas (1-1) to (1-9) and (2-1) to (2-6), a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and a fluorinated alkyl group.

The “acetal-type acid dissociable group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an OH-containing polar group such as a carboxy group or a hydroxyl group. Then, the acid acts to cut the bond between the acetal acid dissociable group and the oxygen atom to which the acetal acid dissociable group is bonded, and OH-containing polar groups such as a carboxy group and a hydroxyl group are formed. The
Examples of the acetal type acid dissociable group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙはアルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group or an aliphatic cyclic group. Represents. ]

In formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
The alkyl group for R ¹ ′ and R ² ′ is preferably a linear or branched alkyl group, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. , Tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like. A methyl group or an ethyl group is preferable, and a methyl group is most preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同じである。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

As the alkyl group for Y, an alkyl group having 1 to 20 carbon atoms is preferable, an alkyl group having 1 to 10 carbon atoms is more preferable; a linear or branched alkyl group is preferable, and specifically, a methyl group , Ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group, 2, A 2-dimethylpropyl group, a 2,2, -dimethylbutyl group, etc. are mentioned.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as the aliphatic cyclic groups mentioned in “Acid-dissociable groups containing formula groups”.

  Examples of the acetal type acid dissociable group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状若しくは分岐鎖状のアルキル基または水素原子であり；Ｒ^１９は直鎖状、分岐鎖状若しくは環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状若しくは分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represents a linear or branched alkyl group or a hydrogen atom; and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. And the like, in which a hydrogen atom is removed. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the formula (p2), R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ¹⁹ is The terminal of R ¹⁷ may be bonded.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  The structural unit (a1) is not particularly limited as long as it has an acid-decomposable group, and an acrylic ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent Is a structural unit derived from an acid-decomposable group, a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and a hydrogen atom bonded to the benzene ring is other than a hydroxyl group A structural unit obtained by substituting a hydrogen atom of a hydroxyl group of a structural unit derived from hydroxystyrene which may be substituted with a substituent of the above, with an acid dissociable group or a substituent containing an acid dissociable group, a carbon atom at the α-position A structural unit derived from vinyl (hydroxynaphthalene) in which the hydrogen atom bonded to the hydrogen atom may be substituted with a substituent, and the hydrogen atom bonded to the naphthalene ring may be substituted with a substituent other than a hydroxyl group A structural unit in which the hydrogen atom of the hydroxyl group is substituted with a substituent containing an acid dissociable group or an acid-dissociable group.

Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
In the acrylate ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent that replaces the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydroxy group. An alkyl group etc. are mentioned. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
Hereinafter, acrylic acid and acrylic ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as α-substituted acrylic acid and α-substituted acrylic ester, respectively. In addition, acrylic acid and α-substituted acrylic acid may be collectively referred to as “(α-substituted) acrylic acid”, and acrylic acid ester and α-substituted acrylic acid ester may be collectively referred to as “(α-substituted) acrylic acid ester”. .
In the α-substituted acrylate ester, the alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, n- Examples thereof include a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a halogen atom. It is done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Bonded to the α-position of the α-substituted acrylate ester is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. An alkyl group or a fluorinated alkyl group having 1 to 5 carbon atoms is more preferred, and a hydrogen atom or a methyl group is most preferred from the viewpoint of industrial availability.

“A structural unit derived from hydroxystyrene or a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
“Hydroxystyrene derivative” is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
The “structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative” means a structural unit configured by cleavage of an ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.
The “vinyl benzoic acid derivative” is a concept including a compound in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.

  Among these, the structural unit (a1) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. , Structural units represented by the following general formula (a1-0-1), structural units represented by the following general formula (a1-0-2), and the like.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；Ｘ^１は酸解離性基であり；Ｙ^２は２価の連結基であり；Ｘ^２は酸解離性基である。］

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; X ¹ is an acid dissociable group; Y ² is a divalent linking group. Yes; X ² is an acid-dissociable group. ]

In general formula (a1-0-1), the alkyl group and the halogenated alkyl group of R are each exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylate ester. And the same alkyl groups and halogenated alkyl groups. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group.
X ¹ is not particularly limited as long as it is an acid dissociable group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable groups, acetal type acid dissociable groups, and the like. An ester type acid dissociable group is preferred.
In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).

Examples of the divalent linking group of Y ^2, but are not limited to, divalent hydrocarbon group which may have a substituent group, and a divalent linking group containing a hetero atom as preferred.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with a substituent (a group or atom other than a hydrogen atom).
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.
The aliphatic hydrocarbon group as the divalent hydrocarbon group in Y ² may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
The alicyclic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group in Y ² preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and 6 to 6 carbon atoms. 15 is particularly preferable, and 6 to 10 is most preferable. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are heterogeneous. Aromatic heterocycles substituted with atoms; and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) ) In which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) Group obtained by further removing one hydrogen atom from the aryl group in the group); and the like. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.
The aromatic hydrocarbon group may or may not have a substituent. For example, a hydrogen atom bonded to the aromatic hydrocarbon ring of the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The hetero atom in the “divalent linking group containing a hetero atom” of Y ² is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
As the divalent linking group containing a hetero atom, —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (= O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, —S (═O) _{2 -O -, - NH-C} (= O) -, = N-, the formula ^{-Y 21 -O-Y 22 -,} - [Y 21 -C (= O) -O] m '-Y 22 - Or a group represented by —Y ²¹ —O—C (═O) —Y ²² —, wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group optionally having a substituent. O is an oxygen atom, and m ′ is an integer of 0 to 3. ] Etc. are mentioned.
When Y ² is —NH—, H may be substituted with a substituent such as an alkyl group or an aryl group (aromatic group). The substituent (alkyl group, aryl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - [Y 21 -C (= O) -O] m '-Y 22 - or ^{-Y 21 -O-C (= O} ) -Y 22 - ^{In, Y 21} And Y ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same groups as those described above as the “divalent hydrocarbon group which may have a substituent” for Y ² .
Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, and more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² —, m ′ is an integer of 0 to 3, preferably an integer of 0 to 2, Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — is represented by the formula —Y ²¹ —C (═O) —O—Y ²² —. The group is particularly preferred. Among these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1.
Examples of the divalent linking group containing a hetero atom, a linear group containing an oxygen atom as a hetero atom, for example, a group containing an ether bond or an ester bond, are preferred, the formula -Y 21 ^-O-Y 22 ^-, A group represented by — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² — is more preferable.

Among these, as the divalent linking group for Y ² , in particular, a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom is included. preferable. Among these, a linear or branched alkylene group or a divalent linking group containing a hetero atom is preferable.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［式中、Ｒ、Ｒ^１’、Ｒ^２’、ｎ、ＹおよびＹ^２はそれぞれ前記と同じであり、Ｘ’は第３級アルキルエステル型酸解離性基を表す。］

[Wherein, R, R ¹ ′, R ² ′, n, Y and Y ² are the same as defined above, and X ′ represents a tertiary alkyl ester-type acid dissociable group. ]

In the formula, X ′ is the same as the tertiary alkyl ester-type acid dissociable group.
^{R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable group" described above ^{(p1) ', R 2'} , n, similarly to the Y Can be mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).
Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  In the present invention, as the structural unit (a1), the above formulas (a1-1-16) to (a1-1-23), (a1-1-27), (a1-1-31) to (a1-1) -33), (a1-1-38), structural units represented by (a1-1-39), tertiary carbon on the aliphatic monocyclic group in X ′ in the formula (a1-1) A structural unit having an atom; structural units represented by the formulas (a1-1-26) and (a1-1-28) to (a1-1-30), and X ′ in the formula (a1-1) A structural unit in which the carbon atom on the aliphatic cyclic group is a tertiary carbon atom, and the carbon atom constituting the tertiary carbon atom is bonded to a branched alkyl group; ) To (a1-1-3), (a1-1-7) to (a1-1-15), a structural unit represented by X ′ in the formula (a1-1). A structural unit having a tertiary carbon atom on the aliphatic polycyclic group; selected from each group of structural units represented by the formulas (a1-3-25) to (a1-3-32) It is preferable to use at least one kind.

As the structural unit (a1), a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and a hydrogen atom bonded to the benzene ring is substituted with a substituent other than a hydroxyl group. Further, a structural unit in which a hydrogen atom of a hydroxyl group of a structural unit derived from hydroxystyrene is substituted with an acid-dissociable group or a substituent containing an acid-dissociable group is also included.
“Hydroxystyrene” is a compound in which one vinyl group and at least one hydroxyl group are bonded to a benzene ring. 1-3 are preferable and, as for the number of the hydroxyl groups couple | bonded with a benzene ring, 1 is especially preferable. The bonding position of the hydroxyl group in the benzene ring is not particularly limited. When the number of hydroxyl groups is one, the para position of the bonding position of the vinyl group is preferable. When the number of hydroxyl groups is an integer of 2 or more, any bonding position can be combined.
Examples of the acid dissociable group for substituting the hydrogen atom of the hydroxyl group include the same groups as those described above, preferably a tertiary alkyl ester type acid dissociable group or an acetal type acid dissociable group, and an acetal type acid dissociable group is More preferred.
Examples of the substituent containing an acid dissociable group include a group composed of an acid dissociable group and a divalent linking group. Examples of the divalent linking group include those similar to the divalent linking group for Q ² in the formula (I), and a group in which the terminal structure on the acid dissociable group side is a carbonyloxy group is particularly preferable. . In this case, it is preferable that an acid dissociable group is bonded to the oxygen atom (—O—) of the carbonyloxy group.
Examples of the substituent containing an acid dissociable group include a group represented by R ¹¹ ′ —O—C (═O) — and a group represented by R ¹¹ ′ —O—C (═O) —R ¹² ′ —. Is preferred. In the formula, R ¹¹ ′ is an acid dissociable group, and R ¹² ′ is a linear or branched alkylene group.
The acid dissociable group for R ¹¹ ′ is preferably a tertiary alkyl ester type acid dissociable group or an acetal type acid dissociable group, more preferably a tertiary alkyl ester type acid dissociable group. As a preferable example of the tertiary alkyl ester type acid dissociable group, the aliphatic branched acid dissociable group represented by the above-described —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ), the formula (1- Examples include groups represented by 1) to (1-9), groups represented by formulas (2-1) to (2-6), and the like.
Examples of the alkylene group for R ¹² ′ include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a 1,1-dimethylethylene group. R ¹² ′ is preferably a linear alkylene group.

As the structural unit (a1), a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and a hydrogen atom bonded to the naphthalene ring is substituted with a substituent other than a hydroxyl group. And a structural unit in which a hydrogen atom of a hydroxyl group of a structural unit derived from vinyl (hydroxynaphthalene) is substituted with an acid-dissociable group or a substituent containing an acid-dissociable group.
“Vinyl (hydroxynaphthalene)” is a compound in which one vinyl group and at least one hydroxyl group are bonded to a naphthalene ring. The vinyl group may be bonded to the 1-position of the naphthalene ring or may be bonded to the 2-position. 1-3 are preferable and, as for the number of the hydroxyl groups couple | bonded with a naphthalene ring, 1 is especially preferable. The bonding position of the hydroxyl group in the naphthalene ring is not particularly limited. In the case where a vinyl group is bonded to the 1-position or 2-position of the naphthalene ring, any one of the 5- to 8-positions of the naphthalene ring is preferable. In particular, when the number of hydroxyl groups is one, any one of 5 to 7 positions of the naphthalene ring is preferable, and 5 or 6 positions are preferable. When the number of hydroxyl groups is an integer of 2 or more, any bonding position can be combined.
Examples of the acid dissociable group for substituting the hydrogen atom of the hydroxyl group and the substituent containing the acid dissociable group include an acid dissociable group for substituting the hydrogen atom of the hydroxyl group of the structural unit derived from hydroxystyrene, and acid dissociation, respectively. Examples thereof include the same substituents containing a functional group.

As the structural unit (a1) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
In the component (A1), the proportion of the structural unit (a1) is preferably 15 to 70 mol%, more preferably 15 to 60 mol%, with respect to the total of all structural units constituting the component (A1). More preferred is mol%.
By setting the proportion of the structural unit (a1) to the lower limit value or more, a pattern can be easily obtained when a resist composition is formed, and lithography properties such as sensitivity, resolution, and roughness are also improved. Moreover, it becomes easy to balance with another structural unit by setting it as an upper limit or less.

[Structural unit (a2)]
The component (A1) preferably further has a structural unit (a2) containing a —SO ₂ — containing cyclic group or a lactone-containing cyclic group in addition to the structural unit (a1).
The —SO ₂ — containing cyclic group or lactone cyclic group of the structural unit (a2) is effective for enhancing the adhesion of the resist film to the substrate when the component (A1) is used for forming the resist film. Is. Moreover, it is effective in the alkali development process in that the affinity with a developer containing water such as an alkali developer is improved.

· -SO 2 _-, where-containing cyclic group, "- SO 2 _- containing cyclic group" is a, -SO 2 _- within the ring skeleton thereof shows a cyclic group containing a ring containing, specifically, , —SO ₂ — is a cyclic group in which the sulfur atom (S) forms part of the cyclic skeleton of the cyclic group. The ring containing —SO ₂ — in the ring skeleton is counted as the first ring, and when it is only the ring, it is a monocyclic group, and when it has another ring structure, it is a polycyclic group regardless of the structure. Called. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
The —SO ₂ — containing cyclic group is particularly a cyclic group containing —O—SO ₂ — in its ring skeleton, that is, —O—S— in —O—SO ₂ — represents a part of the ring skeleton. A cyclic group containing a sultone ring to be formed is preferable.
The —SO ₂ — containing cyclic group preferably has 3 to 30 carbon atoms, more preferably 4 to 20 carbon atoms, still more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms. preferable. However, the carbon number is the number of carbon atoms constituting the ring skeleton, and does not include the carbon number in the substituent.
The —SO ₂ — containing cyclic group may be an —SO ₂ — containing aliphatic cyclic group or an —SO ₂ — containing aromatic cyclic group. Preferably -SO ₂ - containing aliphatic cyclic group.
The —SO ₂ -containing aliphatic cyclic group includes at least a hydrogen atom from an aliphatic hydrocarbon ring in which a part of carbon atoms constituting the ring skeleton is substituted with —SO ₂ — or —O—SO ₂ —. One group is excluded. More specifically, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, —CH ₂ — constituting the ring And a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which CH ₂ — is substituted with —O—SO ₂ —.
The alicyclic hydrocarbon ring preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon ring may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms. Examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon ring, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.

The —SO ₂ — containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, a hydroxyalkyl group, a cyano group, and the like. Is mentioned.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group for the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Examples of the halogenated alkyl group as the substituent include a group in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
R ″ in —COOR ″ and —OC (═O) R ″ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Alternatively, one or more hydrogen atoms are removed from a polycycloalkane such as a monocycloalkane, bicycloalkane, tricycloalkane, or tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group. More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group.
The hydroxyalkyl group as the substituent is preferably one having 1 to 6 carbon atoms. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (3-1) to (3-4).

［式中、Ａ’は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｚは０〜２の整数であり、Ｒ^２７はアルキル基、アルコキシ基、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり、Ｒ”は水素原子またはアルキル基である。］

[In the formula, A ′ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, z is an integer of 0 to 2, and R ²⁷ is an alkyl group. , An alkoxy group, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group, and R ″ is a hydrogen atom or an alkyl group.]

In the general formulas (3-1) to (3-4), A ′ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), An oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ′ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ′ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
z may be any of 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ²⁷ may be the same or different.
As the alkyl group, alkoxy group, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in R ²⁷ , the —SO ₂ — containing cyclic group has the above-mentioned, respectively. And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups as those which may be substituted.

  Specific examples of the cyclic groups represented by the general formulas (3-1) to (3-4) are shown below. In the formula, “Ac” represents an acetyl group.

Among the above, the —SO ₂ -containing cyclic group is preferably a group represented by the general formula (3-1), and the chemical formulas (3-1-1), (3-1-18), ( It is more preferable to use at least one selected from the group consisting of groups represented by any of 3-3-1) and (3-4-1), and represented by the chemical formula (3-1-1). Are most preferred.

Lactone-containing cyclic group “Lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C (═O) — in its ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone cyclic group in the structural unit (a2) is not particularly limited, and any one can be used. Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
More specifically, examples of the lactone-containing cyclic group include groups represented by the following general formulas (4-1) to (4-7).

［式中、Ｒ’はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、酸素原子（＝Ｏ）、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり、Ｒ”は水素原子またはアルキル基であり；ｓ”は０または１〜２の整数であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり；ｍは０または１の整数である。］

[Wherein, R ′ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, hydroxy An alkyl group or a cyano group, R ″ is a hydrogen atom or an alkyl group; s ″ is 0 or an integer of 1 to 2; A ″ is a carbon number of 1 to 1 which may contain an oxygen atom or a sulfur atom. 5 is an alkylene group, an oxygen atom or a sulfur atom; m is an integer of 0 or 1.]

The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group of R ′ each have a —SO ₂ — containing cyclic group. Alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, hydroxyalkyl groups, —COOR ″, —OC (═O) R, which may be enumerated as substituents. Examples thereof include “(R” is the same as above).
A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
s ″ is preferably an integer of 1 to 2.

  Specific examples of cyclic groups represented by the general formulas (4-1) to (4-7) are shown below. In addition, the wavy line in a formula shows a bond.

The structural unit (a2) is not particularly limited as long as it has a —SO ₂ — containing cyclic group or a lactone-containing cyclic group, but the hydrogen atom bonded to the α-position carbon atom is A structural unit derived from an acrylate ester optionally substituted with a substituent, including a structural unit containing an —SO ₂ -containing cyclic group, and a hydrogen atom bonded to the carbon atom at the α-position substituted with the substituent At least one structural unit selected from the group consisting of structural units derived from an acrylate ester which may be prepared and comprising a structural unit containing a lactone-containing cyclic group is preferred.

  More specifically, examples of the structural unit (a2) include structural units represented by general formula (a2-0) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^２８は−ＳＯ_２−含有環式基またはラクトン含有環式基であり、Ｙ^４は単結合または２価の連結基である。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and R ²⁸ is an —SO ₂ — containing cyclic group or a lactone-containing cyclic group. Y ⁴ is a single bond or a divalent linking group. ]

In formula (a2-0), R is the same as defined above.
R ²⁸ is the same as the —SO ₂ -containing cyclic group or the lactone-containing cyclic group mentioned above.
Y ⁴ may be either a single bond or a divalent linking group, but is preferably a divalent linking group.
Examples of the divalent linking group for Y ^4, is not particularly limited, for example, include the same divalent linking group for ^{Y 2} in the (a1-0-2). Among these, those containing an alkylene group or an ester bond (—C (═O) —O—) are preferable.
The alkylene group is preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for Y ² can be used.
As the divalent linking group containing an ester bond, in particular, the general formula: —R ³⁰ —C (═O) —O— [wherein R ³⁰ is a divalent linking group. ] Is preferable.
That is, the structural unit (a2) is preferably a structural unit represented by each of the following general formulas (a2-0-1) to (a2-0-3).

［式中、ＲおよびＲ^２８はそれぞれ前記と同様であり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

[Wherein, R and R ²⁸ are the same as defined above, and c to e are each independently an integer of 1 to 3. ]

  As the structural unit (a2), in particular, structures represented by the following general formulas (a2-1-11), (a2-1-12), (a2-2-11), and (a2-2-12), respectively. A unit is preferable, the structural unit represented by the following general formula (a2-1-12), (a2-2-11), or (a2-2-12) is more preferable, and in the formula (a2-1-12) The structural unit represented is particularly preferred.

［式中、Ｒ、Ａ’、Ｒ^２７、ｚ、Ｒ’、ｓ”、Ａ”はそれぞれ前記と同じである。］

[Wherein, R, A ′, R ²⁷ , z, R ′, s ″, and A ″ are the same as defined above. ]

In the component (A1), the structural unit (a2) may be one type or two or more types.
When the component (A1) contains the structural unit (a2), the proportion of the structural unit (a2) in the component (A1) is 5 to 70 mol based on the total of all structural units constituting the component (A1). % Is preferable, 10 to 65 mol% is more preferable, and 20 to 60 mol% is more preferable.
By setting the proportion of the structural unit (a2) to be equal to or higher than the lower limit value, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the ratio to the upper limit value or less, a balance with other structural units is obtained. Various lithographic properties such as DOF and CDU and pattern shapes are improved.

(Structural unit (a3))
The structural unit (a3) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group Unit.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A0) is increased and the resolution is improved.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group. For example, a resin for a resist composition for an ArF excimer laser can be appropriately selected from those proposed. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), the formula ( The structural unit represented by a3-3) is preferred.

（式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。）

(Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5) And s is an integer of 1 to 3.)

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

  In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

  In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the component (A1). 5 to 25 mol% is more preferable.
By setting the proportion of the structural unit (a3) to be equal to or higher than the lower limit value, the effect of containing the structural unit (a3) is sufficiently obtained, and by setting the ratio to the upper limit value or lower, a balance with other structural units is obtained. be able to.

(Other structural units)
The component (A1) includes other structural units (hereinafter referred to as “structural unit (a4)”) other than the structural units (a0) and (a1) to (a3) as long as the effects of the present invention are not impaired. You may go out.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the above-described structural units (a0) and (a1) to (a3). For the ArF excimer laser and the KrF excimer laser ( A number of hitherto known materials can be used that are preferably used for resist resins such as ArF excimer laser).
As the structural unit (a4), for example, a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, which is an acid non-dissociable aliphatic group A structural unit containing a cyclic group, a structural unit derived from a styrene monomer, a structural unit derived from a vinyl naphthalene monomer, and the like are preferable. Examples of the cyclic group include those similar to those exemplified for the structural unit (a1), such as for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser), etc. A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-7).

［式中、Ｒ^αは前記と同じである。］

[Wherein, R ^α is the same as defined above. ]

As the structural unit (a4), one type may be used alone, or two or more types may be used in combination.
When the component (A1) contains the structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 20 mol% with respect to the total of all the structural units constituting the component (A1). 15 mol% is more preferable and 1-10 mol% is further more preferable.

The component (A1) is a polymer having the structural unit (a0), and is preferably a copolymer having the structural unit (a1) in addition to the structural unit (a0).
Examples of such a copolymer include a copolymer composed of structural units (a0), (a1) and (a2); a copolymer composed of structural units (a0), (a1), (a2) and (a3). A copolymer composed of the structural units (a0), (a1), (a2), (a3) and (a4) can be exemplified.

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, most preferably 2500 to 20000. preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.2 to 2 .5 is most preferred.
In addition, Mn shows a number average molecular weight.

In the component (A0), as the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the component (A0) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, and 100% by mass with respect to the total mass of the component (A0). May be. When the ratio is 25% by mass or more, effects such as lithography characteristics are improved.

The component (A0) may contain a base component other than the component (A1) (hereinafter, this base component is referred to as “component (A2)”) as long as the effects of the present invention are not impaired.
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 4000 and having an acid dissociable group and a hydrophilic group as exemplified in the description of the component (A1) may be used. . Specific examples include those in which some or all of the hydrogen atoms of the hydroxyl group of the compound having a plurality of phenol skeletons are substituted with the acid dissociable group.
Examples of the low molecular weight compound include a sensitizer in a non-chemically amplified g-line or i-line resist, and a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a heat resistance improver. Those substituted with a dissociable group are preferred, and any of them can be used arbitrarily.
Examples of the low molecular weight phenol compound include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxypheny Rumethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2 to 6 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol and xylenol. Of course, it is not limited to these. In particular, a phenol compound having 2 to 6 triphenylmethane skeletons is preferable because of excellent resolution and line edge roughness (LWR). The acid dissociable group is not particularly limited, and examples thereof include those described above.

  In the resist composition of the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<Optional component>
[Component (B)]
In addition to the component (A), the resist composition of the present invention may further contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “component (B)”). .
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１０１は置換基を有していてもよい環式基、又は、置換基を有していてもよい鎖状のアルキル基若しくはアルケニル基であり、Ｙ^１０１は単結合または酸素原子を含む２価の連結基であり、Ｖ^１０１は単結合、アルキレン基、またはフッ素化アルキレン基であり、
Ｒ^１０２はフッ素原子または炭素数１〜５のフッ素化アルキル基であり、Ｒ^１０４、Ｒ^１０５は、それぞれ独立に、炭素数１〜１０のアルキル基またはフッ素化アルキル基であり、互いに結合して環を形成していてもよい。Ｍ^ｍ＋はｍ価の有機カチオンである。］

[Wherein, R ¹⁰¹ represents a cyclic group which may have a substituent, or a chain-like alkyl group or alkenyl group which may have a substituent, and Y ¹⁰¹ represents a single bond or an oxygen atom. V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group,
R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, and R ¹⁰⁴ and R ¹⁰⁵ are each independently an alkyl group having 1 to 10 carbon atoms or a fluorinated alkyl group, and are bonded to each other. A ring may be formed. M ^{m +} is an m-valent organic cation. ]

{Anion part}
The cyclic group which may have a substituent of R ¹⁰¹ may be a cyclic aliphatic hydrocarbon group (aliphatic cyclic group), or an aromatic hydrocarbon group (aromatic cyclic group). It may be a heterocycle containing a heteroatom in the ring.
Examples of the cyclic aliphatic hydrocarbon group for R ¹⁰¹ include an aryl group obtained by removing one hydrogen atom from a monocycloalkane or polycycloalkane, and an adamantyl group and a norbornyl group are preferable.
Examples of the aromatic hydrocarbon group for R ¹⁰¹ include an aromatic hydrocarbon ring or an aryl group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings, and a phenyl group and a naphthyl group are preferable.
Specific examples of the heterocyclic ring in R ¹⁰¹ include groups represented by the following formulas (L1) to (L6) and (S1) to (S4).

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —, wherein R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5, and m is an integer of 0 or 1.]

In the formula, the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ is preferably a methylene group.

In addition to the above, examples of the heterocyclic ring for R ¹⁰¹ include the following.

The cyclic aliphatic hydrocarbon group, aromatic hydrocarbon group and heterocyclic ring of R ¹⁰¹ may have a substituent. Here, the cyclic aliphatic hydrocarbon group, aromatic hydrocarbon group or heterocyclic ring has a substituent means that the hydrogen bonded to the cyclic structure of the cyclic aliphatic hydrocarbon group, aromatic hydrocarbon group or heterocyclic ring. This means that part or all of the atoms are replaced with atoms or groups other than hydrogen atoms. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a nitro group.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and a methoxy group. An ethoxy group is most preferred.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent, a part of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, or the like A group in which all the halogen atoms are substituted is exemplified.

The chain alkyl group for R ¹⁰¹ may be either linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

The alkenyl group for R ¹⁰¹ preferably has 2 to 10 carbon atoms, preferably 2 to 5, more preferably 2 to 4, and particularly preferably 3. For example, a vinyl group, a propenyl group (allyl group), a butynyl group, etc. are mentioned. Among the above, a propenyl group is particularly preferable.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include, for example, the same alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, oxygen atom (═O), nitro as the substituent of the above cyclic group. Group or the above cyclic group.

In the present invention, R ¹⁰¹ is preferably a cyclic group which may have a substituent, a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane, Lactone-containing cyclic groups or —SO ₂ -containing cyclic groups represented by L1) to (L6) and (S1) to (S4), respectively, are preferable.

The divalent linking group containing an oxygen atom of Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group. A sulfonyl group (—SO ₂ —) may be further linked to the combination.
Examples of the combination, for ^{example, -V 105 -O -, - V} 105 -O-C (= O) -, - C (= O) -O-V 105 -O-C (= O) -, - SO _2- O—V ¹⁰⁵ —O—C (═O) —, —V ¹⁰⁵ —SO ₂ —O—V ¹⁰⁶ —O—C (═O) — (wherein V ^{105 to} V ¹⁰⁶ are each independently alkylene. Group.) And the like.
The alkylene group for V ^{105 to} V ¹⁰⁶ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Examples of the alkylene group include the same straight-chain or branched alkylene group exemplified in the description of the Y ² and the like.
Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or an ether bond, and in particular, —V ¹⁰⁵ —O—, —V ¹⁰⁵ —O—C (═O) — or —C (═O) — O—V ¹⁰⁵ —O—C (═O) — is preferable.

^Examples of the alkylene group for V ¹⁰¹ include the same alkylene groups as those described above for V ^{105 to} V ^106, and preferably have 1 to 5 carbon atoms.
^Examples of the fluorinated alkylene group for V ¹⁰¹ include those in which part or all of the hydrogen atoms constituting the alkylene group for V ^{105 to} V ¹⁰⁶ are substituted with fluorine atoms. It is preferable that it is C1-C5, and 1-2 is more preferable.

Examples of the fluorinated alkyl group having 1 to 5 carbon atoms of R ¹⁰² include groups in which some or all of the hydrogen atoms constituting the alkyl group having 1 to 5 carbon atoms are substituted with fluorine atoms.

R ¹⁰⁴ and R ¹⁰⁵ are each independently an alkyl group having 1 to 10 carbon atoms or a fluorinated alkyl group, and may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably linear or branched (fluorinated) alkyl groups. The (fluorinated) alkyl group has 1 to 10 carbon atoms, preferably 1 to 7 carbon atoms, and more preferably 1 to 3 carbon atoms. The number of carbon atoms of the (fluorinated) alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible because of good solubility in a resist solvent within the above carbon number range.
Further, in the (fluorinated) alkyl group of R ¹⁰⁴ and R ^105, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and the transparency to high energy light and electron beams of 200 nm or less. This is preferable because of improved properties. The proportion of fluorine atoms in the (fluorinated) alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are replaced with fluorine atoms. Perfluoroalkylene group or perfluoroalkyl group.

  Specific examples of the anion moiety represented by the formula (b-1) include anions represented by any of the following formulas (b1) to (b9).

［式中、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^７は置換基であり、ｎ１〜ｎ６はそれぞれ独立に０または１であり、ｖ０〜ｖ６はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ６はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 to r2 are each independently 0 to 3] G is an integer of 1 to 20, R ⁷ is a substituent, n1 to n6 are each independently 0 or 1, v0 to v6 are each independently an integer of 0 to 3, w1 to w6 are each independently an integer of 0 to 3, and Q ″ is the same as above.]

Examples of the substituent for R ⁷ include those ^{exemplified in} the description of R ¹⁰¹ as those that may substitute a part of the hydrogen atoms bonded to the carbon atoms constituting the ring structure of the aliphatic cyclic group, The thing similar to what was mentioned as a substituent which may substitute the hydrogen atom couple | bonded with the aromatic ring which an aromatic hydrocarbon group has is mentioned.
Code (r1 and r2, W1 to W6) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, may be different.

  As for the anion moiety, alkyl sulfonates such as methane sulfonate, n-propane sulfonate, n-butane sulfonate, n-octane sulfonate, 1-adamantane sulfonate, 2-norbornane sulfonate; d-camphor- Onium salts substituted with sulfonates such as 10-sulfonate, benzenesulfonate, perfluorobenzenesulfonate, and p-toluenesulfonate can also be used.

{Cation part}
In the formulas (b-1) and (b-2), M ^{m +} is an m-valent organic cation.
The m-valent organic cation in M ^{m +} is not particularly limited, and for example, an organic cation conventionally known as a cation moiety such as an onium salt-based acid generator of a resist composition can be used.
Preferred examples of the m-valent organic cation include a sulfonium cation or an iodonium cation. In addition to the cations represented by the above formulas (ca-1) to (ca-3), the mvalent organic cation is represented by the following general formula (ca-4). Cations are preferred.

［式中、およびＲ^２１１〜Ｒ^２１２は、それぞれ独立に置換基を有していてもよいアリール基、アルキル基またはアルケニル基を表し、Ｒ^２１１〜Ｒ^２１２は、相互に結合して式中のイオウ原子と共に環を形成してもよい。Ｙ^２０１は、それぞれ独立に、アリーレン基、アルキレン基またはアルケニレン基を表し、ｘは１または２であり、Ｗ^２０１は（ｘ＋１）価の連結基を表す。］

Wherein and ^R 211 ^{to R 212} each independently optionally substituted aryl group, an alkyl group or alkenyl ^group, R 211 ^{to R 212} is in the formula are bonded to each other You may form a ring with a sulfur atom. Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group, x is 1 or 2, and W ²⁰¹ represents a (x + 1) -valent linking group. ]

Examples of the aryl group in R ^{211 to} R ²¹² include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group for R ^{211 to} R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ^{211 to} R ²¹² preferably has 2 to 10 carbon atoms.

The substituent that R ^{211 to} R ²¹² may have is the same as the substituent that R ^{201 in} formula (ca-1) may have.
When R ^{211 to} R ²¹² are bonded to each other and form a ring together with the sulfur atom in the formula, they are the same as the case where R ^{201 to} R ²⁰³ in the formula (ca-1) form a ring.

x is 1 or 2.
W ²⁰¹ is a (x + 1) valent, that is, a divalent or trivalent linking group.
Examples of the divalent linking group in W ²⁰¹ include the same divalent linking groups as Y ^{2 in} the above formula (a1-0-2), which may be linear, branched, or cyclic. There may be, and it is preferable that it is cyclic. Of these, a group in which two carbonyl groups are combined at both ends of the arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
^Examples of the trivalent linking group in W ²⁰¹ include a group in which one hydrogen atom has been removed from a divalent linking group, and a group in which a divalent linking group is further bonded to a divalent linking group. Examples of the divalent linking group include those similar to the divalent linking group of Y ^{2 in} the above formula (a1-0-2). The trivalent linking group in W ¹ is preferably a group in which three carbonyl groups are combined with an arylene group.

  Specific examples of suitable cations of formula (ca-4) include cations represented by the following formulas.

The organic cation in M ^{m +} is preferably a sulfonium cation represented by the formula (ca-1) or (ca-3).

As the oxime sulfonate acid generator, an oxime sulfonate acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014], [Chem. 18] to [Chem. 19]), International Publication An oxime sulfonate-based acid generator disclosed in No. 04/074242 (Examples 1 to 40 on pages 65 to 86) can be preferably used.
As the diazomethane acid generator, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552 and JP-A-11-035573 can be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

As the component (B), one type of acid generator described above may be used alone, or two or more types may be used in combination.
0.5-60 mass parts is preferable with respect to 100 mass parts of (A) component, as for content of (B) component in the resist composition of this invention, 1-50 mass parts is more preferable, 1-40 mass parts Is more preferable. By forming the content of the component (B) within the above range, pattern formation is sufficiently performed. Moreover, when each component of a resist composition is melt | dissolved in the organic solvent, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

[(D) component]
In the resist composition of the present invention, a nitrogen-containing organic compound component (D) (hereinafter referred to as “(D)” which does not fall under the components (A) and (B), as long as the effects of the present invention are not impaired. Component ")).
As the component (D), an acid diffusion control agent, that is, the component (A) (structural unit (a0)) or the component (A) (structural unit (a0)) and the component (B) is generated by exposure. There is no particular limitation as long as it acts as a quencher for trapping acid, and a wide variety of those have already been proposed. Examples thereof include amines such as aliphatic amines and aromatic amines, among which aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.

An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 20 carbon atoms.
Examples of the aliphatic amine include amines (alkyl amines or alkyl alcohol amines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 1 to 20 carbon atoms. It is done.
The alkyl group and the alkyl group in the hydroxyalkyl group may be linear, branched or cyclic.
When the alkyl group is linear or branched, the carbon number thereof is more preferably 2-20, and further preferably 2-8.
When the alkyl group is cyclic (when it is a cycloalkyl group), the carbon number is preferably 3 to 30, more preferably 3 to 20, still more preferably 3 to 15, and 4 to 12 carbon atoms. It is particularly preferred that the number of carbon atoms is 5-10. The alkyl group may be monocyclic or polycyclic. Specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkane, groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as bicycloalkane, tricycloalkane, and tetracycloalkane. . Specific examples of the monocycloalkane include cyclopentane and cyclohexane. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
Specific examples of the alkylamine include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di-n- Dialkylamines such as heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri- Examples include trialkylamines such as n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, and tri-n-dodecylamine.
Specific examples of the alkyl alcohol amine include diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine, stearyl diethanolamine, lauryldiethanolamine and the like.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.

Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2- (1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxyethoxy) ) Ethoxy} ethyl] amine and the like.
Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, and tribenzylamine.

(D) A component may be used independently and may be used in combination of 2 or more type.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

[(E) component]
The resist composition of the present invention is a group consisting of organic carboxylic acid, phosphorus oxo acid and derivatives thereof as optional components for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, etc. May contain at least one compound (E) (hereinafter referred to as “component (E)”) selected from:
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of phosphinic acid derivatives include phenylphosphinic acid and phosphinic acid esters.
(E) A component may be used individually by 1 type and may use 2 or more types together.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

[(F) component]
The resist composition of the present invention may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film. By further containing the component (F), the hydrophobicity of the resist film surface is increased and the occurrence of defects after development is further suppressed.
As the component (F), for example, a fluorine-containing polymer compound described in JP 2010-002870 A can be used.
Specific examples of the component (F) include a copolymer having a structural unit represented by the following general formula (f1). More specifically, a polymer consisting of only a structural unit represented by the following formula (f1) (homopolymer); a copolymer of the structural unit represented by the following formula (f1) and the structural unit (a1) A copolymer of a structural unit represented by the following formula (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1) is preferable.
Among the structural units (a1), the structural unit represented by the formula (a1-1-32) is particularly preferable.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基であり、Ｒ^７”はフッ素原子を含む有機基であり、Ｒ^８”は置換基を有していてもよい炭素数１〜５のアルキレン基である。］

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ⁷ ″ is an organic group containing a fluorine atom, and R ⁸ ″ is a substituent. It is a C1-C5 alkylene group which may have. ]

In the formula (f1), R ⁷ ″ is an organic group containing a fluorine atom, preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom is more preferably a fluorinated alkyl group. Further, a fluorinated alkyl group having 1 to 5 carbon atoms is more preferable. Among them, as R ⁷ ″, a group represented by “— (CH ₂ ) o—CF ₃ ” is preferable (wherein, o is CH _2). Is an integer of 1 to 3).
In formula (f1), the carbon number of the alkylene group of R ⁸ ″ is 1 to 5, preferably 1 to 3, and more preferably 1 or 2. The hydrogen atom of the alkylene group of R ⁸ ″. May be substituted with a fluorine atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms.
In the formula (f1), R is the same as described above. R is preferably a hydrogen atom or a methyl group.
(F) A component may be used individually by 1 type and may use 2 or more types together.
The content of the component (F) in the resist composition is preferably 1 to 10 parts by mass per 100 parts by mass of the component (A). By making content of (F) component into the said range, the hydrophobicity of the resist film surface increases, and the defect generation after image development is suppressed more.

  The resist composition of the present invention may further contain, if desired, miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving coatability, a dissolution inhibitor, Plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be added and contained as appropriate.

[(S) component]
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as “(S) component”).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, γ-butyrolactone, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range. For example, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3. Further, when PGME and cyclohexanone are blended as polar solvents, the mass ratio of PGMEA: (PGME + cyclohexanone) is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, and even more preferably 3. : 7 to 7: 3.
In addition, as the component (S), PGMEA, EL or a mixed solvent of PGMEA and a polar solvent and a mixed solvent of γ-butyrolactone are also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of the component (S) used is not particularly limited and is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. Generally, the solid content concentration of the resist composition is It is used in a range of 1 to 20% by mass, preferably 2 to 15% by mass.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and developing the resist film to form a resist pattern. Forming.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition of the present invention is applied onto a support with a spinner or the like, and baking (post-apply bake (PAB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds. Preferably, it is applied for 60 to 90 seconds to form a resist film.
Next, the resist film is exposed through a mask (mask pattern) on which a predetermined pattern is formed using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, or a mask pattern. After performing selective exposure by drawing or the like by direct irradiation with an electron beam without passing through, baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 Apply for ~ 90 seconds.
Next, the resist film is developed.
The development treatment is performed using an alkaline developer in the case of an alkali development process, and using a developer (organic developer) containing an organic solvent in the case of a solvent development process.
A rinsing treatment is preferably performed after the development treatment. The rinse treatment is preferably a water rinse using pure water in the case of an alkali development process, and is preferably a rinse solution containing an organic solvent in the case of a solvent development process.
In the case of a solvent development process, after the development process or the rinse process, a process of removing the developer or rinse liquid adhering to the pattern with a supercritical fluid may be performed.
Drying is performed after development or rinsing. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning a lower organic film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
In the multilayer resist method, basically, a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).

The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV.

The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure (Liquid Immersion Lithography).
In immersion exposure, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in that state. It is an exposure method.
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film to be exposed is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).
As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility, and the like.

Examples of the alkali developer used for the development treatment in the alkali development process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for the development process in the solvent development process is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure). It can be selected as appropriate. Specifically, polar solvents or hydrocarbon solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents and the like can be used.
A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0. 0% with respect to the total amount of the organic developer. 5 mass% is more preferable.
The development treatment can be carried out by a known development method, for example, a method in which a support is immersed in a developer for a certain period of time (dip method), and the developer is raised on the surface of the support by surface tension and left stationary for a certain period of time. Method (Paddle method), Method of spraying developer on the surface of support (spray method), Continuous application of developer while scanning developer coating nozzle at constant speed on support rotating at constant speed And a method (dynamic dispensing method).

As the organic solvent contained in the rinsing liquid used for the rinsing treatment after the development process in the solvent development process, for example, among the organic solvents mentioned as the organic solvent contained in the organic developer, those which are difficult to dissolve the resist pattern are appropriately used. You can select and use. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The rinse treatment (washing treatment) using the rinse liquid can be performed by a known rinse method. Examples of the method include a method of continuously applying a rinsing liquid on a support rotating at a constant speed (rotary coating method), a method of immersing the support in a rinsing liquid for a predetermined time (dip method), and the surface of the support. And a method of spraying a rinse liquid (spray method).

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
In this example, the compound represented by the chemical formula (1) is referred to as “compound (1)”, and the same applies to compounds represented by other chemical formulas.
In the analysis by NMR, the internal standard of ¹ H-NMR and the internal standard of ¹³ C-NMR is tetramethylsilane (TMS).

Example 1: Production Example of Polymer Compound 3
Obtaining a first precursor polymer:
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 40.00 g (126.5 mmol) of Compound 1, 57.43 g (245.1 mmol) of Compound 2, and 16.99 g (39. 00 mmol) of compound 3 was dissolved in 143.9 g of a mixed solvent of methyl ethyl ketone and cyclohexanone (MEK / CH). To this solution, 28.74 mmol of dimethyl azobisisobutyrate (V-601) was added and dissolved as a polymerization initiator. Next, this was dropped into 79.75 g MEK / CH over 4 hours in a nitrogen atmosphere to carry out the reaction. After completion of the dropwise addition, the reaction solution was stirred for 1 hour while heating, and then the reaction solution was cooled to room temperature. Subsequently, the obtained reaction polymerization liquid is dropped into a large amount of n-heptane, and a polymer is precipitated. The precipitated white powder is filtered off, washed with methanol and dried to obtain a polymer compound. 1 (first precursor polymer) 79.10 g was obtained.

Amine reaction process:
39.5 g of polymer compound 1 was placed in an eggplant flask, 2.87 g of compound 4 (amine), 158 g of acetonitrile and 158 g of n-heptane were added and stirred for 30 minutes, and then the acetonitrile layer was extracted. did. The extracted acetonitrile layer was dropped into a large amount of diisopropyl ether, and a polymer was precipitated. The precipitated white powder was filtered off and dried to obtain polymer compound 2 (second precursor polymer) 33. 0.1 g was obtained.
[About pKa]
The pKa of the conjugate acid (second ammonium cation) in compound 4 (amine) is 10.98, and the pKa of the ammonium cation (first ammonium cation) in polymer compound 1 is 6.28. That is, the conjugate acid (second ammonium cation) has a larger pKa than the first ammonium cation.
[About hydrophobicity]
The retention time of the ammonium cation (second ammonium cation) in the polymer compound 2 is 2.2 minutes, and the retention time of the first ammonium cation in the polymer compound 1 is 3.6 minutes. That is, the second ammonium cation is less hydrophobic than the first ammonium cation.

Salt exchange process:
33.1 g of the polymer compound 2 was put in an eggplant flask, 6.11 g of the compound 5, 132 g of dichloromethane and 132 g of water were added and stirred for 30 minutes, and then the organic layer was extracted. The extracted organic layer was dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder was filtered and dried to obtain 33.1 g of polymer compound 3.
About this high molecular compound 3, the mass mean molecular weight (Mw) of standard polystyrene conversion calculated | required by GPC measurement was 12400, and molecular weight dispersion degree (Mw / Mn) was 1.56. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n = 44.2 / 41. 5 / 14.3.
[About hydrophobicity]
The retention time of the second ammonium cation in the polymer compound 2 is 2.2 minutes, and the retention time of the sulfonium cation in the compound 5 is 2.6 minutes. That is, the second ammonium cation is less hydrophobic than the sulfonium cation.

(Comparative Example 1)
39.5 g of the polymer compound 1 was put in an eggplant flask, 7.03 g of the compound 5, 158 g of dichloromethane and 158 g of water were added and stirred for 30 minutes, and then the organic layer was extracted. The extracted organic layer was dropped into a large amount of n-heptane to precipitate a polymer, but only the polymer compound 1 was recovered, but the polymer compound 3 was not obtained.
The recovered polymer compound 1 had a standard polystyrene equivalent mass average molecular weight (Mw) of 12600 determined by GPC measurement and a molecular weight dispersity (Mw / Mn) of 1.62. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 44.0 / 41. 8 / 14.2.
[About hydrophobicity]
The retention time of ammonium cation in polymer compound 1 is 3.6 minutes, and the retention time of sulfonium cation in compound 5 is 2.6 minutes. That is, the ammonium cation in the polymer compound 1 is more hydrophobic than the sulfonium cation.

(Comparative Example 2)
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 10.00 g (31.61 mmol) of Compound 1, 14.36 g (61.27 mmol) of Compound 2, and 4.55 g (9. 75 mmol) of Compound 6 was dissolved in 36.35 g of a mixed solvent of methyl ethyl ketone and cyclohexanone (MEK / CH). To this solution, 7.18 mmol of dimethyl azobisisobutyrate (V-601) was added and dissolved as a polymerization initiator. Next, this was dropped into 20.15 g of MEK / CH over 4 hours in a nitrogen atmosphere to carry out the reaction. After completion of the dropwise addition, the reaction solution was stirred for 1 hour while heating to produce a white solid.
This white solid was separated by filtration and analyzed by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR). As a result, deprotection of compound 2 was confirmed, and polymer compound 3 was not obtained. In addition, mass average molecular weight (Mw), molecular weight dispersity (Mw / Mn) and copolymer composition ratio were not measurable.

(Example 2: Production Example of Polymer Compound 7)
Obtaining a first precursor polymer:
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 40.00 g (126.5 mmol) of Compound 1, 57.43 g (245.1 mmol) of Compound 2, and 19.21 g (39. 00 mmol) of Compound 7 was dissolved in 146.7 g of a mixed solvent of methyl ethyl ketone and cyclohexanone (MEK / CH). To this solution, 28.74 mmol of dimethyl azobisisobutyrate (V-601) was added and dissolved as a polymerization initiator. Next, this was dropped into 81.30 g of MEK / CH over 4 hours in a nitrogen atmosphere to react. After completion of the dropwise addition, the reaction solution was stirred for 1 hour while heating, and then the reaction solution was cooled to room temperature. Subsequently, the obtained reaction polymerization liquid is dropped into a large amount of n-heptane, and a polymer is precipitated. The precipitated white powder is filtered off, washed with methanol and dried to obtain a polymer compound. 41.2 (3rd precursor polymer) was obtained.
Next, 81.2 g of the polymer compound 4 was placed in an eggplant flask, 21.2 g of compound 8 (salt), 325 g of MEK and 325 g of water were added and stirred for 30 minutes, and then the organic layer was removed. Extracted. The extracted organic layer is dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder is filtered off and dried to obtain polymer compound 5 (first precursor polymer). 73.3 g was obtained.
[About hydrophobicity]
The retention time of the sulfonium cation in the polymer compound 4 is 2.7 minutes, and the retention time of the ammonium cation (first ammonium cation) in the compound 8 (salt) is 3.6 minutes. That is, the first ammonium cation is more hydrophobic than the sulfonium cation.

Amine reaction process:
A polymer compound 6 (second precursor) was used in the same manner as in the amine reaction step (using compound 4 as an amine) in Example 1 except that the polymer compound 5 was used instead of the polymer compound 1. Polymer; chemical structure was the same as that of the polymer compound 2).
[About pKa]
The pKa of the conjugate acid (second ammonium cation) in compound 4 (amine) is 10.98, and the pKa of the ammonium cation (first ammonium cation) in polymer compound 5 is 6.28. That is, the conjugate acid (second ammonium cation) has a larger pKa than the first ammonium cation.
[About hydrophobicity]
The retention time of the ammonium cation (second ammonium cation) in the polymer compound 6 is 2.2 minutes, and the retention time of the first ammonium cation in the polymer compound 5 is 3.6 minutes. That is, the second ammonium cation is less hydrophobic than the first ammonium cation.

Salt exchange process:
A polymer compound 7 (chemical structure is the same as that of the polymer compound 3) is obtained in the same manner as in the salt exchange step in Example 1 except that the polymer compound 6 is used instead of the polymer compound 2. It was.
With respect to this polymer compound 7, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 12600, and the molecular weight dispersity (Mw / Mn) was 1.54. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 43.8 / 42. 0.0 / 14.2.
[About hydrophobicity]
The retention time of the second ammonium cation in the polymer compound 6 is 2.2 minutes, and the retention time of the sulfonium cation in the compound 5 is 2.6 minutes. That is, the second ammonium cation is less hydrophobic than the sulfonium cation.

(Comparative Example 3)
5.00 g of polymer compound 4 was placed in an eggplant flask, 0.84 g of compound 5, 20.0 g of dichloromethane and 20.0 g of water were added and stirred for 30 minutes, and then the organic layer was extracted. . The extracted organic layer was dropped into a large amount of n-heptane to deposit a polymer, but only the polymer compound 4 was recovered, and the polymer compound 3 was not obtained.
With respect to the recovered polymer compound 4, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 12900, and the molecular weight dispersity (Mw / Mn) was 1.71. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n = 45.1 / 40. 4 / 14.5.
[About hydrophobicity]
The retention time of the sulfonium cation in the polymer compound 4 is 2.7 minutes, and the retention time of the sulfonium cation in the compound 5 is 2.6 minutes. That is, the sulfonium cation in the polymer compound 4 is more hydrophobic than the sulfonium cation in the compound 5.

(Comparative Example 4)
The acetonitrile layer was extracted in the same manner as in the amine reaction step in Example 1, except that the polymer compound 1 was used and the compound 9 was used as the amine instead of the compound 4. The extracted acetonitrile layer was dropped into a large amount of diisopropyl ether to perform the operation of precipitating the polymer, but only the polymer compound 1 was recovered, and the polymer compound 8 was not obtained.
The recovered polymer compound 1 had a mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement of 12600, and the molecular weight dispersity (Mw / Mn) was 1.61. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 44.1 / 41. 9 / 14.0.
[About pKa]
The pKa of the conjugate acid (ammonium cation) in compound 9 (amine) is 4.25, and the pKa of the ammonium cation in polymer compound 1 is 6.28. That is, the conjugate acid (ammonium cation) has a smaller pKa than the ammonium cation in the polymer compound 1.
[About hydrophobicity]
The retention time of the ammonium cation in the polymer compound 8 is 6.0 minutes, and the retention time of the ammonium cation in the polymer compound 1 is 3.6 minutes. That is, the ammonium cation in the polymer compound 8 is more hydrophobic than the ammonium cation in the polymer compound 1.

(Example 3)
When synthesizing the third precursor polymer, the first precursor polymer is obtained in the same manner as in Example 2 except that Compound 10 is used in addition to Compound 1, Compound 2, and Compound 7. The polymer compound 9 was obtained by performing the steps of the step, the amine reaction step (using compound 4 as the amine) and the salt exchange step.
For this polymer compound 9, the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 11700, and the molecular weight dispersity (Mw / Mn) was 1.80. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n / o = 36.2. /33.4/17.1/13.3.

Example 4
Except for using Compound 11 in place of Compound 2, the procedures for obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine), and the salt exchange step were performed in the same manner as in Example 1. And the polymer compound 10 was obtained.
With respect to this polymer compound 10, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 12000, and the molecular weight dispersity (Mw / Mn) was 1.76. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n = 44.9 / 40. .8 / 14.3.

(Example 5)
Except for using Compound 12 in place of Compound 2, the procedure for obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine) and the salt exchange step were performed in the same manner as in Example 1. And the polymer compound 11 was obtained.
With respect to the polymer compound 11, the mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 13500, and the molecular weight dispersity (Mw / Mn) was 1.59. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 45.5 / 41. 7 / 12.8.

(Example 6)
When synthesizing the third precursor polymer, the first precursor polymer is obtained in the same manner as in Example 2 except that Compound 12 is used in addition to Compound 1, Compound 2, and Compound 3. The polymer compound 12 was obtained by carrying out operations of a step, an amine reaction step (using compound 4 as an amine) and a salt exchange step.
With respect to this polymer compound 12, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 13700, and the molecular weight dispersity (Mw / Mn) was 1.83. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n / o = 43.2. /21.2/20.7/14.9.

(Example 7)
Except that Compound 13 was used instead of Compound 2, the steps of obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine) and the salt exchange step were performed in the same manner as in Example 1. And polymer compound 13 was obtained.
With respect to this polymer compound 13, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 13400, and the molecular weight dispersity (Mw / Mn) was 1.68. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 46.2 / 41. It was .5 / 12.3.

(Example 8)
Except for using Compound 14 instead of Compound 5, the same procedures as in Example 1 were followed for the steps of obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine), and the salt exchange step. And polymer compound 14 was obtained.
With respect to this polymer compound 14, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 12500, and the molecular weight dispersity (Mw / Mn) was 1.56. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 44.4 / 41. 0.0 / 14.6.
[Relationship between hydrophobicity in salt exchange process]
The retention time of the second ammonium cation in the polymer compound 2 is 2.2 minutes, and the retention time of the sulfonium cation in the compound 14 is 2.3 minutes. That is, the second ammonium cation is less hydrophobic than the sulfonium cation.

Example 9
Except for using Compound 15 in place of Compound 1, the procedures for obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine), and the salt exchange step were performed in the same manner as in Example 1. And polymer compound 15 was obtained.
With respect to this polymer compound 15, the standard polystyrene equivalent mass average molecular weight (Mw) determined by GPC measurement was 13100, and the molecular weight dispersity (Mw / Mn) was 1.60. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 45.5 / 41. 4 / 13.1.

(Example 10)
Except for using Compound 16 in place of Compound 1, the procedures for obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine), and the salt exchange step were performed in the same manner as in Example 1. And polymer compound 16 was obtained.
With respect to this polymer compound 16, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 12000, and the molecular weight dispersity (Mw / Mn) was 1.81. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 42.7 / 45. It was 0.0 / 122.3.

(Example 11)
Except for using Compound 17 in place of Compound 1, the procedures for obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine), and the salt exchange step were performed in the same manner as in Example 1. And polymer compound 17 was obtained.
For this polymer compound 17, the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 12800, and the molecular weight dispersity (Mw / Mn) was 1.67. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 43.0 / 44. 9 / 12.1.

(Example 12)
Except that Compound 18 was used instead of Compound 3, the steps of obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine) and the salt exchange step were performed in the same manner as in Example 1. And polymer compound 18 was obtained.
With respect to this polymer compound 18, the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 11,500, and the molecular weight dispersity (Mw / Mn) was 1.71. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 44.1 / 41. 9 / 14.0.

(Example 13)
Except that Compound 19 was used instead of Compound 3, the steps of obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine) and the salt exchange step were performed in the same manner as in Example 1. And polymer compound 19 was obtained.
With respect to this polymer compound 19, the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 12500, and the molecular weight dispersity (Mw / Mn) was 1.59. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n = 44.5 / 41 8 / 13.7.
[Relationship of pKa in amine reaction process]
The pKa of the conjugate acid (second ammonium cation) in compound 4 (amine) is 10.98, and the pKa of the first ammonium cation in the first precursor polymer is 4.25. That is, the conjugate acid (second ammonium cation) has a larger pKa than the first ammonium cation.
[Relationship between hydrophobicity in amine reaction process]
The retention time of the second ammonium cation in the second precursor polymer is 2.2 minutes and the retention time of the first ammonium cation in the first precursor polymer is 6.0 minutes. That is, the second ammonium cation is less hydrophobic than the first ammonium cation.
[Relationship between hydrophobicity in salt exchange process]
The retention time of the second ammonium cation in the second precursor polymer is 2.2 minutes, and the retention time of the sulfonium cation in compound 5 is 2.6 minutes. That is, the second ammonium cation is less hydrophobic than the sulfonium cation.

(Example 14)
Except for using Compound 20 in place of Compound 3, the procedures for obtaining the first precursor polymer, the amine reaction step (using Compound 4 as the amine), and the salt exchange step were performed in the same manner as in Example 1. And polymer compound 20 was obtained.
With respect to this polymer compound 20, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 12500, and the molecular weight dispersity (Mw / Mn) was 1.61. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n = 44.2 / 41. 3 / 14.5.
[Relationship of pKa in amine reaction process]
The pKa of the conjugate acid (second ammonium cation) in compound 4 (amine) is 10.98, and the pKa of the first ammonium cation in the first precursor polymer is 6.23. That is, the conjugate acid (second ammonium cation) has a larger pKa than the first ammonium cation.
[Relationship between hydrophobicity in amine reaction process]
The retention time of the second ammonium cation in the second precursor polymer is 2.2 minutes and the retention time of the first ammonium cation in the first precursor polymer is 12.9 minutes. That is, the second ammonium cation is less hydrophobic than the first ammonium cation.
[Relationship between hydrophobicity in salt exchange process]
The retention time of the second ammonium cation in the second precursor polymer is 2.2 minutes, and the retention time of the sulfonium cation in compound 5 is 2.6 minutes. That is, the second ammonium cation is less hydrophobic than the sulfonium cation.

(Example 15)
Except that Compound 21 was used instead of Compound 4, the steps of obtaining the first precursor polymer, the amine reaction step, and the salt exchange step were performed in the same manner as in Example 1 to obtain the polymer compound 21. It was.
With respect to this polymer compound 21, the polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 12300, and the molecular weight dispersity (Mw / Mn) was 1.62. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 43.7 / 42. 0.0 / 14.3.
[Relationship of pKa in amine reaction process]
The pKa of the conjugate acid (second ammonium cation) in compound 21 (amine) is 10.62, and the pKa of the first ammonium cation in the first precursor polymer is 6.28. That is, the conjugate acid (second ammonium cation) has a larger pKa than the first ammonium cation.
[Relationship between hydrophobicity in amine reaction process]
The retention time of the second ammonium cation in the second precursor polymer is 2.2 minutes and the retention time of the first ammonium cation in the first precursor polymer is 3.6 minutes. That is, the second ammonium cation is less hydrophobic than the first ammonium cation.
[Relationship between hydrophobicity in salt exchange process]
The retention time of the second ammonium cation in the second precursor polymer is 2.2 minutes, and the retention time of the sulfonium cation in compound 5 is 2.6 minutes. That is, the second ammonium cation is less hydrophobic than the sulfonium cation.

(Example 16)
Except that compound 22 was used instead of compound 4, the steps of obtaining the first precursor polymer, the amine reaction step and the salt exchange step were carried out in the same manner as in Example 1 to obtain polymer compound 22. It was.
With respect to the polymer compound 22, the mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 12400, and the molecular weight dispersity (Mw / Mn) was 1.57. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m / n = 44.0 / 41. .6 / 14.4.
[Relationship of pKa in amine reaction process]
The pKa of the conjugate acid (second ammonium cation) in compound 22 (amine) is 9.52, and the pKa of the first ammonium cation in the first precursor polymer is 6.28. That is, the conjugate acid (second ammonium cation) has a larger pKa than the first ammonium cation.
[Relationship between hydrophobicity in amine reaction process]
The retention time of the second ammonium cation in the second precursor polymer is 2.2 minutes and the retention time of the first ammonium cation in the first precursor polymer is 3.6 minutes. That is, the second ammonium cation is less hydrophobic than the first ammonium cation.
[Relationship between hydrophobicity in salt exchange process]
The retention time of the second ammonium cation in the second precursor polymer is 2.2 minutes, and the retention time of the sulfonium cation in compound 5 is 2.6 minutes. That is, the second ammonium cation is less hydrophobic than the sulfonium cation.

<Preparation of resist composition>
(Examples 17 to 20)
Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

In Table 1, the numerical value in [] is a blending amount (part by mass), and each abbreviation has the following meaning.
(A) -1: The polymer compound 3 produced in Example 1.
(A) -2: The polymer compound 7 produced in Example 2.
(A) -12: The polymer compound 18 produced in Example 12.
(B) -1: The following compound (B) -1.
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(F) -1: the following polymer compound (F) -1 (Mw18000, Mw / Mn1.5; in the chemical formula, the numerical value at the lower right of the structural unit () indicates the proportion (molar ratio) of the structural unit) .
(S) -1: PGMEA / PGME / cyclohexanone = 45/30/25 (mass ratio) mixed solvent.

<Formation of resist pattern>
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a film thickness of 89 nm was formed.
Next, each of the above resist compositions is applied onto the organic antireflection film using a spinner, pre-baked (PAB) at 110 ° C. for 60 seconds on a hot plate, and dried to form a film. A resist film having a thickness of 90 nm was formed.
Subsequently, an ArF excimer laser (193 nm) is applied to the resist film on which the top coat is formed through a mask by an ArF immersion exposure apparatus NSR-S609B (manufactured by Nikon; NA (numerical aperture) = 1.07). ) Was selectively irradiated.
Then, post-exposure heating (PEB) treatment was performed at 130 ° C. for Examples 17, 18 and 20 and at 100 ° C. for Example 19 for 60 seconds, respectively, and further, 2.38 mass% tetramethyl ammonium hydroxy at 23 ° C. (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was subjected to alkali development for 10 seconds, then rinsed with pure water for 30 seconds, and then shaken and dried.
Subsequently, post-baking was performed at 100 ° C. for 45 seconds.
As a result, in each example, a line-and-space resist pattern in which line patterns with a width of 49 nm were arranged at equal intervals (pitch 98 nm) was formed on the resist film.

As shown in Examples 1 to 16 above, the present invention has been applied so far by a novel production method of a polymer compound having a structural unit that decomposes upon exposure to generate an acid, and thus has been directly polymerized. It was possible to obtain a polymer compound having a final sulfonium or iodonium cation that was difficult to obtain.
Such a polymer compound is particularly useful as a material for a photoresist composition that forms a resist pattern with good lithography properties as shown in Examples 17 to 20.

Claims (6)

A first precursor polymer having a first ammonium cation is reacted with an amine whose acid dissociation constant (pKa) of the conjugate acid is larger than that of the first ammonium cation, to thereby form a second conjugate acid of the amine. Obtaining a second precursor polymer having a plurality of ammonium cations;
Salt exchange between the second precursor polymer and the sulfonium cation or iodonium cation,
The second ammonium cation has a lower hydrophobicity than the first ammonium cation and has a lower hydrophobicity than the sulfonium cation or the iodonium cation, and generates an acid upon decomposition by exposure. A method for producing a polymer compound having a structural unit.   A step of obtaining a first precursor polymer by salt exchange between a third precursor polymer having a sulfonium cation or an iodonium cation and the first ammonium cation having higher hydrophobicity than the sulfonium cation or the iodonium cation. The manufacturing method of the high molecular compound of Claim 1 containing.   The manufacturing method of the high molecular compound of Claim 1 or 2 with which the said 1st precursor polymer has a structural unit containing the acid-decomposable group which polarity increases by the effect | action of an acid.   The resist composition containing the high molecular compound manufactured by the manufacturing method of the high molecular compound as described in any one of Claims 1-3.   A resist pattern forming process comprising: forming a resist film on the support using the resist composition according to claim 4; exposing the resist film; and developing the resist film to form a resist pattern. Method. A first precursor polymer having a first ammonium cation;
A polymer characterized in that an acid dissociation constant (pKa) of a conjugate acid is larger than that of the first ammonium cation and an amine having a hydrophobicity of the conjugate acid is lower than that of the first ammonium cation. Compound production method.